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<td align="right" valign="top" width="230"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></td></tr></table><h1 align="center">QString Class Reference</h1>

The QString class provides a Unicode character string. <a href="#details">More...</a>

<pre>#include <QString></pre>Part of the <a href="qtcore.html">QtCore</a> module.

Note: All the functions in this class are <a href="threads.html#reentrant">reentrant</a>.

<ul>

<li><a href="qstring-members.html">List of all members, including inherited members</a></li>

<li><a href="qstring-qt3.html">Qt 3 support members</a></li>

</ul>

<h3>Public Types</h3>

<ul>

<li><div class="fn"/>class <a href="qstring-null.html">Null</a></li>

<li><div class="fn"/>enum <a href="qstring.html#NormalizationForm-enum">NormalizationForm</a> { NormalizationForm_D, NormalizationForm_C, NormalizationForm_KD, NormalizationForm_KC }</li>

<li><div class="fn"/>enum <a href="qstring.html#SectionFlag-enum">SectionFlag</a> { SectionDefault, SectionSkipEmpty, SectionIncludeLeadingSep, SectionIncludeTrailingSep, SectionCaseInsensitiveSeps }</li>

<li><div class="fn"/>flags <a href="qstring.html#SectionFlag-enum">SectionFlags</a></li>

<li><div class="fn"/>enum <a href="qstring.html#SplitBehavior-enum">SplitBehavior</a> { KeepEmptyParts, SkipEmptyParts }</li>

</ul>

<h3>Public Functions</h3>

<ul>

<li><div class="fn"/><a href="qstring.html#QString">QString</a> ()</li>

<li><div class="fn"/><a href="qstring.html#QString-2">QString</a> ( const QChar * unicode, int size )</li>

<li><div class="fn"/><a href="qstring.html#QString-3">QString</a> ( QChar ch )</li>

<li><div class="fn"/><a href="qstring.html#QString-4">QString</a> ( int size, QChar ch )</li>

<li><div class="fn"/><a href="qstring.html#QString-5">QString</a> ( const QLatin1String & str )</li>

<li><div class="fn"/><a href="qstring.html#QString-6">QString</a> ( const QString & other )</li>

<li><div class="fn"/><a href="qstring.html#QString-7">QString</a> ( const char * str )</li>

<li><div class="fn"/><a href="qstring.html#QString-8">QString</a> ( const QByteArray & ba )</li>

<li><div class="fn"/><a href="qstring.html#dtor.QString">~QString</a> ()</li>

<li><div class="fn"/>QString & <a href="qstring.html#append">append</a> ( const QString & str )</li>

<li><div class="fn"/>QString & <a href="qstring.html#append-2">append</a> ( const QLatin1String & str )</li>

<li><div class="fn"/>QString & <a href="qstring.html#append-3">append</a> ( const QByteArray & ba )</li>

<li><div class="fn"/>QString & <a href="qstring.html#append-4">append</a> ( const char * str )</li>

<li><div class="fn"/>QString & <a href="qstring.html#append-5">append</a> ( QChar ch )</li>

<li><div class="fn"/>QString <a href="qstring.html#arg">arg</a> ( const QString & a, int fieldWidth = 0, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-2">arg</a> ( const QString & a1, const QString & a2 ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-3">arg</a> ( const QString & a1, const QString & a2, const QString & a3 ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-4">arg</a> ( const QString & a1, const QString & a2, const QString & a3, const QString & a4 ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-5">arg</a> ( int a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-6">arg</a> ( uint a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-7">arg</a> ( long a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-8">arg</a> ( ulong a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-9">arg</a> ( qlonglong a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-10">arg</a> ( qulonglong a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-11">arg</a> ( short a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-12">arg</a> ( ushort a, int fieldWidth = 0, int base = 10, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-13">arg</a> ( QChar a, int fieldWidth = 0, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-14">arg</a> ( char a, int fieldWidth = 0, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>QString <a href="qstring.html#arg-15">arg</a> ( double a, int fieldWidth = 0, char fmt = 'g', int prec = -1, const QChar & fillChar = QLatin1Char( ' ' ) ) const</li>

<li><div class="fn"/>const QChar <a href="qstring.html#at">at</a> ( int i ) const</li>

<li><div class="fn"/>int <a href="qstring.html#capacity">capacity</a> () const</li>

<li><div class="fn"/>void <a href="qstring.html#clear">clear</a> ()</li>

<li><div class="fn"/>int <a href="qstring.html#compare-2">compare</a> ( const QString & other ) const</li>

<li><div class="fn"/>const QChar * <a href="qstring.html#constData">constData</a> () const</li>

<li><div class="fn"/>bool <a href="qstring.html#contains">contains</a> ( const QString & str, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>bool <a href="qstring.html#contains-4">contains</a> ( QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>bool <a href="qstring.html#contains-5">contains</a> ( const QRegExp & rx ) const</li>

<li><div class="fn"/>int <a href="qstring.html#count">count</a> ( const QString & str, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#count-2">count</a> ( QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#count-3">count</a> ( const QRegExp & rx ) const</li>

<li><div class="fn"/>int <a href="qstring.html#count-4">count</a> () const</li>

<li><div class="fn"/>QChar * <a href="qstring.html#data">data</a> ()</li>

<li><div class="fn"/>const QChar * <a href="qstring.html#data-2">data</a> () const</li>

<li><div class="fn"/>bool <a href="qstring.html#endsWith">endsWith</a> ( const QString & s, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>bool <a href="qstring.html#endsWith-3">endsWith</a> ( const QLatin1String & s, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>bool <a href="qstring.html#endsWith-4">endsWith</a> ( const QChar & c, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>QString & <a href="qstring.html#fill">fill</a> ( QChar ch, int size = -1 )</li>

<li><div class="fn"/>int <a href="qstring.html#indexOf">indexOf</a> ( const QString & str, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#indexOf-2">indexOf</a> ( QChar ch, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#indexOf-3">indexOf</a> ( const QRegExp & rx, int from = 0 ) const</li>

<li><div class="fn"/>QString & <a href="qstring.html#insert">insert</a> ( int i, const QString & str )</li>

<li><div class="fn"/>QString & <a href="qstring.html#insert-2">insert</a> ( int i, const QLatin1String & str )</li>

<li><div class="fn"/>QString & <a href="qstring.html#insert-3">insert</a> ( int i, const QChar * unicode, int size )</li>

<li><div class="fn"/>QString & <a href="qstring.html#insert-4">insert</a> ( int i, QChar ch )</li>

<li><div class="fn"/>bool <a href="qstring.html#isEmpty">isEmpty</a> () const</li>

<li><div class="fn"/>bool <a href="qstring.html#isNull">isNull</a> () const</li>

<li><div class="fn"/>int <a href="qstring.html#lastIndexOf">lastIndexOf</a> ( const QString & str, int from = -1, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#lastIndexOf-2">lastIndexOf</a> ( QChar ch, int from = -1, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

<li><div class="fn"/>int <a href="qstring.html#lastIndexOf-3">lastIndexOf</a> ( const QRegExp & rx, int from = -1 ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#left">left</a> ( int len ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#leftJustified">leftJustified</a> ( int width, QChar fill = QLatin1Char( ' ' ), bool truncate = false ) const</li>

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<li><div class="fn"/>int <a href="qstring.html#length">length</a> () const</li>

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<li><div class="fn"/>int <a href="qstring.html#localeAwareCompare-2">localeAwareCompare</a> ( const QString & other ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#mid">mid</a> ( int i, int len = -1 ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#normalized">normalized</a> ( NormalizationForm form ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#normalized-2">normalized</a> ( NormalizationForm form, QChar::UnicodeVersion version ) const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#prepend">prepend</a> ( const QString & str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#prepend-2">prepend</a> ( const QLatin1String & str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#prepend-3">prepend</a> ( const QByteArray & ba )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#prepend-4">prepend</a> ( const char * str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#prepend-5">prepend</a> ( QChar ch )</li>

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<li><div class="fn"/>void <a href="qstring.html#push_back">push_back</a> ( const QString & other )</li>

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<li><div class="fn"/>void <a href="qstring.html#push_back-2">push_back</a> ( QChar ch )</li>

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<li><div class="fn"/>void <a href="qstring.html#push_front">push_front</a> ( const QString & other )</li>

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<li><div class="fn"/>void <a href="qstring.html#push_front-2">push_front</a> ( QChar ch )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#remove">remove</a> ( int pos, int len )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#remove-4">remove</a> ( const QString & str, Qt::CaseSensitivity cs = Qt::CaseSensitive )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#remove-5">remove</a> ( QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#remove-6">remove</a> ( const QRegExp & rx )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace">replace</a> ( int pos, int len, const QString & after )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-6">replace</a> ( int pos, int len, const QChar * unicode, int size )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-7">replace</a> ( int pos, int len, QChar after )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-8">replace</a> ( const QString & before, const QString & after, Qt::CaseSensitivity cs = Qt::CaseSensitive )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-9">replace</a> ( QChar ch, const QString & after, Qt::CaseSensitivity cs = Qt::CaseSensitive )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-10">replace</a> ( QChar before, QChar after, Qt::CaseSensitivity cs = Qt::CaseSensitive )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#replace-11">replace</a> ( const QRegExp & rx, const QString & after )</li>

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<li><div class="fn"/>void <a href="qstring.html#reserve">reserve</a> ( int size )</li>

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<li><div class="fn"/>void <a href="qstring.html#resize">resize</a> ( int size )</li>

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<li><div class="fn"/>QString <a href="qstring.html#right">right</a> ( int len ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#rightJustified">rightJustified</a> ( int width, QChar fill = QLatin1Char( ' ' ), bool truncate = false ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#section">section</a> ( QChar sep, int start, int end = -1, SectionFlags flags = SectionDefault ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#section-2">section</a> ( const QString & sep, int start, int end = -1, SectionFlags flags = SectionDefault ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#section-3">section</a> ( const QRegExp & reg, int start, int end = -1, SectionFlags flags = SectionDefault ) const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum">setNum</a> ( int n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-2">setNum</a> ( uint n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-3">setNum</a> ( long n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-4">setNum</a> ( ulong n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-5">setNum</a> ( qlonglong n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-6">setNum</a> ( qulonglong n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-7">setNum</a> ( short n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-8">setNum</a> ( ushort n, int base = 10 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-9">setNum</a> ( double n, char f = 'g', int prec = 6 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setNum-10">setNum</a> ( float n, char f = 'g', int prec = 6 )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setUnicode">setUnicode</a> ( const QChar * unicode, int size )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#setUtf16">setUtf16</a> ( const ushort * unicode, int size )</li>

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<li><div class="fn"/>QString <a href="qstring.html#simplified">simplified</a> () const</li>

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<li><div class="fn"/>int <a href="qstring.html#size">size</a> () const</li>

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<li><div class="fn"/>QStringList <a href="qstring.html#split">split</a> ( const QString & sep, SplitBehavior behavior = KeepEmptyParts, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

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<li><div class="fn"/>QStringList <a href="qstring.html#split-2">split</a> ( const QChar & sep, SplitBehavior behavior = KeepEmptyParts, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

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<li><div class="fn"/>QStringList <a href="qstring.html#split-3">split</a> ( const QRegExp & rx, SplitBehavior behavior = KeepEmptyParts ) const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#sprintf">sprintf</a> ( const char * cformat, ... )</li>

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<li><div class="fn"/>void <a href="qstring.html#squeeze">squeeze</a> ()</li>

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<li><div class="fn"/>bool <a href="qstring.html#startsWith">startsWith</a> ( const QString & s, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#startsWith-3">startsWith</a> ( const QLatin1String & s, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#startsWith-4">startsWith</a> ( const QChar & c, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const</li>

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<li><div class="fn"/>QByteArray <a href="qstring.html#toAscii">toAscii</a> () const</li>

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<li><div class="fn"/>double <a href="qstring.html#toDouble">toDouble</a> ( bool * ok = 0 ) const</li>

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<li><div class="fn"/>float <a href="qstring.html#toFloat">toFloat</a> ( bool * ok = 0 ) const</li>

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<li><div class="fn"/>int <a href="qstring.html#toInt">toInt</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>QByteArray <a href="qstring.html#toLatin1">toLatin1</a> () const</li>

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<li><div class="fn"/>QByteArray <a href="qstring.html#toLocal8Bit">toLocal8Bit</a> () const</li>

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<li><div class="fn"/>long <a href="qstring.html#toLong">toLong</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>qlonglong <a href="qstring.html#toLongLong">toLongLong</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#toLower">toLower</a> () const</li>

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<li><div class="fn"/>short <a href="qstring.html#toShort">toShort</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>std::string <a href="qstring.html#toStdString">toStdString</a> () const</li>

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<li><div class="fn"/>std::wstring <a href="qstring.html#toStdWString">toStdWString</a> () const</li>

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<li><div class="fn"/>uint <a href="qstring.html#toUInt">toUInt</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>ulong <a href="qstring.html#toULong">toULong</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>qulonglong <a href="qstring.html#toULongLong">toULongLong</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>ushort <a href="qstring.html#toUShort">toUShort</a> ( bool * ok = 0, int base = 10 ) const</li>

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<li><div class="fn"/>QString <a href="qstring.html#toUpper">toUpper</a> () const</li>

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<li><div class="fn"/>QByteArray <a href="qstring.html#toUtf8">toUtf8</a> () const</li>

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<li><div class="fn"/>QString <a href="qstring.html#trimmed">trimmed</a> () const</li>

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<li><div class="fn"/>void <a href="qstring.html#truncate">truncate</a> ( int pos )</li>

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<li><div class="fn"/>const QChar * <a href="qstring.html#unicode">unicode</a> () const</li>

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<li><div class="fn"/>const ushort * <a href="qstring.html#utf16">utf16</a> () const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#vsprintf">vsprintf</a> ( const char * cformat, va_list ap )</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-not-eq">operator!=</a> ( const QString & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-not-eq-2">operator!=</a> ( const QLatin1String & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-not-eq-3">operator!=</a> ( const QByteArray & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-not-eq-4">operator!=</a> ( const char * other ) const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq">operator+=</a> ( const QString & other )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq-2">operator+=</a> ( const QLatin1String & str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq-3">operator+=</a> ( const QByteArray & ba )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq-4">operator+=</a> ( const char * str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq-5">operator+=</a> ( char ch )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-2b-eq-6">operator+=</a> ( QChar ch )</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt">operator<</a> ( const QString & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-2">operator<</a> ( const QLatin1String & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-3">operator<</a> ( const QByteArray & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-4">operator<</a> ( const char * other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-eq">operator<=</a> ( const QString & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-eq-2">operator<=</a> ( const QLatin1String & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-eq-3">operator<=</a> ( const QByteArray & other ) const</li>

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<li><div class="fn"/>bool <a href="qstring.html#operator-lt-eq-4">operator<=</a> ( const char * other ) const</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq">operator=</a> ( const QString & other )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq-3">operator=</a> ( const QLatin1String & str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq-4">operator=</a> ( const QByteArray & ba )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq-5">operator=</a> ( const char * str )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq-6">operator=</a> ( char ch )</li>

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<li><div class="fn"/>QString & <a href="qstring.html#operator-eq-7">operator=</a> ( QChar ch )</li>

203

<li><div class="fn"/>bool <a href="qstring.html#operator-eq-eq">operator==</a> ( const QString & other ) const</li>

204

<li><div class="fn"/>bool <a href="qstring.html#operator-eq-eq-2">operator==</a> ( const QLatin1String & other ) const</li>

205

<li><div class="fn"/>bool <a href="qstring.html#operator-eq-eq-3">operator==</a> ( const QByteArray & other ) const</li>

206

<li><div class="fn"/>bool <a href="qstring.html#operator-eq-eq-4">operator==</a> ( const char * other ) const</li>

207

<li><div class="fn"/>bool <a href="qstring.html#operator-gt">operator></a> ( const QString & other ) const</li>

208

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-2">operator></a> ( const QLatin1String & other ) const</li>

209

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-3">operator></a> ( const QByteArray & other ) const</li>

210

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-4">operator></a> ( const char * other ) const</li>

211

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-eq">operator>=</a> ( const QString & other ) const</li>

212

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-eq-2">operator>=</a> ( const QLatin1String & other ) const</li>

213

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-eq-3">operator>=</a> ( const QByteArray & other ) const</li>

214

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-eq-4">operator>=</a> ( const char * other ) const</li>

215

<li><div class="fn"/>QCharRef <a href="qstring.html#operator-5b-5d">operator[]</a> ( int i )</li>

216

<li><div class="fn"/>const QChar <a href="qstring.html#operator-5b-5d-2">operator[]</a> ( int i ) const</li>

217

<li><div class="fn"/>QCharRef <a href="qstring.html#operator-5b-5d-3">operator[]</a> ( uint i )</li>

218

<li><div class="fn"/>const QChar <a href="qstring.html#operator-5b-5d-4">operator[]</a> ( uint i ) const</li>

219

</ul>

220

221

<h3>Static Public Members</h3>

222

<ul>

223

<li><div class="fn"/>int <a href="qstring.html#compare">compare</a> ( const QString & s1, const QString & s2 )</li>

224

<li><div class="fn"/>QString <a href="qstring.html#fromAscii">fromAscii</a> ( const char * str, int size = -1 )</li>

225

<li><div class="fn"/>QString <a href="qstring.html#fromLatin1">fromLatin1</a> ( const char * str, int size = -1 )</li>

226

<li><div class="fn"/>QString <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a> ( const char * str, int size = -1 )</li>

227

<li><div class="fn"/>QString <a href="qstring.html#fromRawData">fromRawData</a> ( const QChar * unicode, int size )</li>

228

<li><div class="fn"/>QString <a href="qstring.html#fromStdString">fromStdString</a> ( const std::string & str )</li>

229

<li><div class="fn"/>QString <a href="qstring.html#fromStdWString">fromStdWString</a> ( const std::wstring & str )</li>

230

<li><div class="fn"/>QString <a href="qstring.html#fromUtf8">fromUtf8</a> ( const char * str, int size = -1 )</li>

231

<li><div class="fn"/>QString <a href="qstring.html#fromUtf16">fromUtf16</a> ( const ushort * unicode, int size = -1 )</li>

232

<li><div class="fn"/>int <a href="qstring.html#localeAwareCompare">localeAwareCompare</a> ( const QString & s1, const QString & s2 )</li>

233

<li><div class="fn"/>QString <a href="qstring.html#number">number</a> ( long n, int base = 10 )</li>

234

<li><div class="fn"/>QString <a href="qstring.html#number-2">number</a> ( ulong n, int base = 10 )</li>

235

<li><div class="fn"/>QString <a href="qstring.html#number-3">number</a> ( int n, int base = 10 )</li>

236

<li><div class="fn"/>QString <a href="qstring.html#number-4">number</a> ( uint n, int base = 10 )</li>

237

<li><div class="fn"/>QString <a href="qstring.html#number-5">number</a> ( qlonglong n, int base = 10 )</li>

238

<li><div class="fn"/>QString <a href="qstring.html#number-6">number</a> ( qulonglong n, int base = 10 )</li>

239

<li><div class="fn"/>QString <a href="qstring.html#number-7">number</a> ( double n, char f = 'g', int prec = 6 )</li>

240

</ul>

241

242

<h3>Related Non-Members</h3>

243

<ul>

244

<li><div class="fn"/>bool <a href="qstring.html#operator-not-eq-30">operator!=</a> ( const char * s1, const QString & s2 )</li>

245

<li><div class="fn"/>const QString <a href="qstring.html#operator-2b-7">operator+</a> ( const QString & s1, const QString & s2 )</li>

246

<li><div class="fn"/>const QString <a href="qstring.html#operator-2b-20">operator+</a> ( const QString & s1, const char * s2 )</li>

247

<li><div class="fn"/>const QString <a href="qstring.html#operator-2b-21">operator+</a> ( const char * s1, const QString & s2 )</li>

248

<li><div class="fn"/>const QString <a href="qstring.html#operator-2b-22">operator+</a> ( const QString & s, char ch )</li>

249

<li><div class="fn"/>const QString <a href="qstring.html#operator-2b-23">operator+</a> ( char ch, const QString & s )</li>

250

<li><div class="fn"/>bool <a href="qstring.html#operator-lt-11">operator<</a> ( const char * s1, const QString & s2 )</li>

251

<li><div class="fn"/>QDataStream & <a href="qstring.html#operator-lt-lt-52">operator<<</a> ( QDataStream & out, const QString & str )</li>

252

<li><div class="fn"/>bool <a href="qstring.html#operator-lt-eq-11">operator<=</a> ( const char * s1, const QString & s2 )</li>

253

<li><div class="fn"/>bool <a href="qstring.html#operator-eq-eq-40">operator==</a> ( const char * s1, const QString & s2 )</li>

254

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-11">operator></a> ( const char * s1, const QString & s2 )</li>

255

<li><div class="fn"/>bool <a href="qstring.html#operator-gt-eq-11">operator>=</a> ( const char * s1, const QString & s2 )</li>

256

<li><div class="fn"/>QDataStream & <a href="qstring.html#operator-gt-gt-33">operator>></a> ( QDataStream & in, QString & str )</li>

257

</ul>

258

259

<hr />

260

<h2>Detailed Description</h2>

261

The QString class provides a Unicode character string.

262

QString stores a string of 16-bit <a href="qchar.html">QChar</a>s, where each <a href="qchar.html">QChar</a> stores one Unicode 4.0 character. <a href="unicode.html">Unicode</a> is an international standard that supports most of the writing systems in use today. It is a superset of ASCII and Latin-1 (ISO 8859-1), and all the ASCII/Latin-1 characters are available at the same code positions.

263

Behind the scenes, QString uses <a href="shclass.html#implicit-sharing">implicit sharing</a> (copy-on-write) to reduce memory usage and to avoid the needless copying of data. This also helps reduce the inherent overhead of storing 16-bit characters instead of 8-bit characters.

264

In addition to QString, Qt also provides the <a href="qbytearray.html">QByteArray</a> class to store raw bytes and traditional 8-bit '\0'-terminated strings. For most purposes, QString is the class you want to use. It is used throughout the Qt API, and the Unicode support ensures that your applications will be easy to translate if you want to expand your application's market at some point. The two main cases where <a href="qbytearray.html">QByteArray</a> is appropriate are when you need to store raw binary data, and when memory conservation is critical (e.g. with Qt/Embedded).

265

One way to initialize a QString is simply to pass a <tt>const char *</tt> to its constructor. For example, the following code creates a QString of size 5 containing the data "Hello":

266

<pre>  QString str = "Hello";</pre>

267

QString converts the <tt>const char *</tt> data into Unicode using <a href="qstring.html#fromAscii">fromAscii</a>(). By default, <a href="qstring.html#fromAscii">fromAscii</a>() treats character above 128 as Latin-1 characters, but this can be changed by calling <a href="qtextcodec.html#setCodecForCStrings">QTextCodec::setCodecForCStrings</a>().

268

In all of the QString methods that take <tt>const char *</tt> parameters, the <tt>const char *</tt> is interpreted as a classic C-style '\0'-terminated string. It is legal for the <tt>const char *</tt> parameter to be 0.

269

You can also provide string data as an array of <a href="qchar.html">QChar</a>s:

270

<pre>  static const QChar data[4] = { 0x0055, 0x006e, 0x10e3, 0x03a3 };

271

QString str(data, 4);</pre>

272

QString makes a deep copy of the <a href="qchar.html">QChar</a> data, so you can modify it later without experiencing side effects. (If for performance reasons you don't want to take a deep copy of the character data, use <a href="qstring.html#fromRawData">QString::fromRawData</a>() instead.)

273

Another approach is to set the size of the string using <a href="qstring.html#resize">resize</a>() and to initialize the data character per character. QString uses 0-based indexes, just like C++ arrays. To access the character at a particular index position, you can use operator[](). On non-const strings, operator[]() returns a reference to a character that can be used on the left side of an assignment. For example:

274

<pre>  QString str;

275

str.resize(4);

276

str[0] = QChar('U');

277

str[1] = QChar('n');

278

str[2] = QChar(0x10e3);

279

str[3] = QChar(0x03a3);</pre>

280

For read-only access, an alternative syntax is to use <a href="qstring.html#at">at</a>():

281

<pre>  for (int i = 0; i < str.size(); ++i) {

282

if (str.at(i) >= QChar('a') && str.at(i) <= QChar('f'))

283

cout << "Found character in range [a-f]" << endl;

284

}</pre>

285

<a href="qstring.html#at">at</a>() can be faster than operator[](), because it never causes a <a href="shclass.html#deep-copy">deep copy</a> to occur.

286

To extract several characters at a time, use <a href="qstring.html#left">left</a>(), <a href="qstring.html#right">right</a>(), or <a href="qstring.html#mid">mid</a>().

287

A QString can embed '\0' characters (<a href="qchar.html#SpecialCharacter-enum">QChar::null</a>). The <a href="qstring.html#size">size</a>() function always returns the size of the whole string, including embedded '\0' characters.

288

After a call to <a href="qstring.html#resize">resize</a>(), newly allocated characters have undefined values. To set all the characters in the string to a particular value, call <a href="qstring.html#fill">fill</a>().

289

QString provides dozens of overloads designed to simplify string usage. For example, if you want to compare a QString with a string literal, you can write code like this and it will work as expected:

290

<pre>  if (str == "auto" || str == "extern"

291

|| str == "static" || str == "register") {

292

...

293

}</pre>

294

You can also pass string literals to functions that take QStrings and the QString(const char *) constructor will be invoked. Similarly, you can pass a QString to a function that takes a <tt>const char *</tt> and <a href="qstring-qt3.html#operator-const-char--2a">operator const char *</a>() will be invoked.

295

QString provides the following basic functions for modifying the character data: <a href="qstring.html#append">append</a>(), <a href="qstring.html#prepend">prepend</a>(), <a href="qstring.html#insert">insert</a>(), <a href="qstring.html#replace">replace</a>(), and <a href="qstring.html#remove">remove</a>(). For example:

296

<pre>  QString str = "and";

297

str.prepend("rock "); // str == "rock and"

298

str.append(" roll"); // str == "rock and roll"

299

str.replace(5, 3, "&"); // str == "rock & roll"</pre>

300

The <a href="qstring.html#replace">replace</a>() and <a href="qstring.html#remove">remove</a>() functions' first two arguments are the position from which to start erasing and the number of characters that should be erased.

301

A frequent requirement is to remove whitespace characters from a string ('\n', '\t', ' ', etc.). If you want to remove whitespace from both ends of a QString, use <a href="qstring.html#trimmed">trimmed</a>(). If you want to remove whitespace from both ends and replace multiple consecutive whitespaces with a single space character within the string, use <a href="qstring.html#simplified">simplified</a>().

302

If you want to find all occurrences of a particular character or substring in a QString, use <a href="qstring.html#indexOf">indexOf</a>() or <a href="qstring.html#lastIndexOf">lastIndexOf</a>(). The former searches forward starting from a given index position, the latter searches backward. Both return the index position of the character or substring if they find it; otherwise, they return -1. For example, here's a typical loop that finds all occurrences of a particular substring:

303

<pre>  QString str = "We must be bold, very bold";

304

int j = 0;

305

while ((j = str.indexOf("", j)) != -1) {

306

cout << "Found tag at index position " << j << endl;

307

++j;

308

}</pre>

309

If you want to see if a QString starts or ends with a particular substring use <a href="qstring.html#startsWith">startsWith</a>() or <a href="qstring.html#endsWith">endsWith</a>(). If you simply want to check whether a QString contains a particular character or substring, use <a href="qstring.html#contains">contains</a>(). If you want to find out how many times a particular character or substring occurs in the string, use <a href="qstring.html#count">count</a>().

310

QString provides many functions for converting numbers into strings and strings into numbers. See the <a href="qstring.html#arg">arg</a>() functions, the <a href="qstring.html#setNum">setNum</a>() functions, the <a href="qstring.html#number">number</a>() static functions, and the <a href="qstring.html#toInt">toInt</a>(), <a href="qstring.html#toDouble">toDouble</a>(), and similar functions.

311

To get an upper or lower case version of a string use <a href="qstring.html#toUpper">toUpper</a>() or <a href="qstring.html#toLower">toLower</a>().

312

If you want to replace all occurrences of a particular substring with another, use one of the two-parameter <a href="qstring.html#replace">replace</a>() overloads.

313

QStrings can be compared using overloaded operators such as operator<(), operator<=(), operator==(), operator>=(), and so on. The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. <a href="qstring.html#localeAwareCompare">QString::localeAwareCompare</a>() is a better choice for sorting user-interface strings.

314

Lists of strings are handled by the <a href="qstringlist.html">QStringList</a> class. You can split a string into a list of strings using <a href="qstring.html#split">split</a>(), and join a list of strings into a single string with an optional separator using <a href="qstringlist.html#join">QStringList::join</a>(). You can obtain a list of strings from a string list that contain a particular substring or that match a particular <a href="qregexp.html">QRegExp</a> using <a href="qlist-qt3.html#find">QStringList::find</a>().

315

If you are building a QString gradually and know in advance approximately how many characters the QString will contain, you can call <a href="qstring.html#reserve">reserve</a>(), asking QString to preallocate a certain amount of memory. You can also call <a href="qstring.html#capacity">capacity</a>() to find out how much memory QString actually allocated.

316

To obtain a pointer to the actual character data, call <a href="qstring.html#data">data</a>() or <a href="qstring.html#constData">constData</a>(). These functions return a pointer to the beginning of the <a href="qchar.html">QChar</a> data. The pointer is guaranteed to remain valid until a non-const function is called on the QString.

317

318

<h3>Conversions between 8-bit strings and Unicode strings</h3>

319

QString provides the following four functions that return a <tt>const char *</tt> version of the string as <a href="qbytearray.html">QByteArray</a>: <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), and <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>().

320

<ul>

321

<li><a href="qstring.html#toAscii">toAscii</a>() returns an ASCII encoded 8-bit string.</li>

322

<li><a href="qstring.html#toLatin1">toLatin1</a>() returns a Latin-1 (ISO 8859-1) encoded 8-bit string.</li>

323

<li><a href="qstring.html#toUtf8">toUtf8</a>() returns a UTF-8 encoded 8-bit string. UTF-8 is a superset of ASCII that supports the entire Unicode character set through multibyte sequences.</li>

324

<li><a href="qstring.html#toLocal8Bit">toLocal8Bit</a>() returns an 8-bit string using the system's local encoding.</li>

325

</ul>

326

To convert from one of these encodings, QString provides <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#fromUtf8">fromUtf8</a>(), and <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>(). Other encodings are supported through <a href="qtextcodec.html">QTextCodec</a>.

327

As mentioned above, QString provides a lot of functions and operators that make it easy to interoperate with <tt>const char *</tt> strings. This functionaly is a two-edged sword: It makes QString more convenient to use if all strings are ASCII or Latin-1, but there is always the risk that an implicit conversion from or to <tt>const char *</tt> is done using the wrong 8-bit encoding. To minimize these risks, you can turn off these implicit conversions by defining these two preprocessor symbols:

328

<ul>

329

<li><tt>QT_NO_CAST_FROM_ASCII</tt> disables automatic conversions from ASCII to Unicode.</li>

330

<li><tt>QT_NO_CAST_TO_ASCII</tt> disables automatic conversion from QString to ASCII.</li>

331

</ul>

332

One way to define these prepocessor symbols globally for your application is to add the following entry to your <a href="qmake-project-files.html">qmake project file</a>:

333

<pre>  DEFINES += QT_NO_CAST_FROM_ASCII \

334

QT_NO_CAST_TO_ASCII</pre>

335

You then need to explicitly call <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#fromUtf8">fromUtf8</a>(), or <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>() to construct a QString from an 8-bit string, or use the lightweight <a href="qlatin1string.html">QLatin1String</a> class, for example:

336

<pre>  QString url = QLatin1String("http://www.unicode.org/");</pre>

337

Similarly, you must call <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), or <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>() explicitly to convert the QString to an 8-bit string. (Other encodings are supported through <a href="qtextcodec.html">QTextCodec</a>.)

338

339

<h3>Note for C programmers</h3>

340

Due to C++'s type system and the fact that QString is <a href="shclass.html#implicitly-shared">implicitly shared</a>, QStrings may be treated like <tt>int</tt>s or other basic types. For example:

341

<pre>  QString boolToString(bool b)

342

{

343

QString result;

344

if (b)

345

result = "True";

346

else

347

result = "False";

348

return result;

349

}</pre>

350

The variable, result, is a normal variable allocated on the stack. When return is called, because we're returning by value, The copy constructor is called and a copy of the string is returned. (No actual copying takes place thanks to the implicit sharing.)

351

352

<h3>Distinction between null and empty strings</h3>

353

For historical reasons, QString distinguishes between a null string and an empty string. A null string is a string that is initialized using QString's default constructor or by passing (const char *)0 to the constructor. An empty string is any string with size 0. A null string is always empty, but an empty string isn't necessarily null:

354

<pre>  QString().isNull(); // returns true

355

QString().isEmpty(); // returns true

356

357

QString("").isNull(); // returns false

358

QString("").isEmpty(); // returns true

359

360

QString("abc").isNull(); // returns false

361

QString("abc").isEmpty(); // returns false</pre>

362

All functions except <a href="qstring.html#isNull">isNull</a>() treat null strings the same as empty strings. For example, <a href="qstring.html#toAscii">toAscii</a>().<a href="qstring.html#constData">constData</a>() returns a pointer to a '\0' character for a null string (not a null pointer), and <a href="qstring.html#QString">QString</a>() compares equal to QString(""). We recommend that you always use <a href="qstring.html#isEmpty">isEmpty</a>() and avoid <a href="qstring.html#isNull">isNull</a>().

363

See also <a href="qstring.html#fromRawData">fromRawData</a>(), <a href="qchar.html">QChar</a>, <a href="qlatin1string.html">QLatin1String</a>, and <a href="qbytearray.html">QByteArray</a>.

364

<hr />

365

<h2>Member Type Documentation</h2>

366

<h3 class="fn"><a name="NormalizationForm-enum"></a>enum QString::NormalizationForm</h3>

367

368

<tr><th width="25%">Constant</th><th width="15%">Value</th><th width="60%">Description</th></tr>

369

<tr><td valign="top"><tt>QString::NormalizationForm_D</tt></td><td align="center" valign="top"><tt>0</tt></td><td valign="top">Canonical Decomposition</td></tr>

370

<tr><td valign="top"><tt>QString::NormalizationForm_C</tt></td><td align="center" valign="top"><tt>1</tt></td><td valign="top">Canonical Decomposition followed by Canonical Composition</td></tr>

371

<tr><td valign="top"><tt>QString::NormalizationForm_KD</tt></td><td align="center" valign="top"><tt>2</tt></td><td valign="top">Compatibility Decomposition</td></tr>

372

<tr><td valign="top"><tt>QString::NormalizationForm_KC</tt></td><td align="center" valign="top"><tt>3</tt></td><td valign="top">Compatibility Decomposition followed by Canonical Composition</td></tr>

373

</table>

374

See also <a href="qstring.html#normalized">normalized</a>() and <a href="http://www.unicode.org/reports/tr15/">Unicode Standard Annex #15</a>.

375

<h3 class="flags"><a name="SectionFlag-enum"></a>enum QString::SectionFlag flags QString::SectionFlags</h3>

376

377

<tr><th width="25%">Constant</th><th width="15%">Value</th><th width="60%">Description</th></tr>

378

<tr><td valign="top"><tt>QString::SectionDefault</tt></td><td align="center" valign="top"><tt>0x00</tt></td><td valign="top">Empty fields are counted, leading and trailing separators are not included, and the separator is compared case sensitively.</td></tr>

379

<tr><td valign="top"><tt>QString::SectionSkipEmpty</tt></td><td align="center" valign="top"><tt>0x01</tt></td><td valign="top">Treat empty fields as if they don't exist, i.e. they are not considered as far as start and end are concerned.</td></tr>

380

<tr><td valign="top"><tt>QString::SectionIncludeLeadingSep</tt></td><td align="center" valign="top"><tt>0x02</tt></td><td valign="top">Include the leading separator (if any) in the result string.</td></tr>

381

<tr><td valign="top"><tt>QString::SectionIncludeTrailingSep</tt></td><td align="center" valign="top"><tt>0x04</tt></td><td valign="top">Include the trailing separator (if any) in the result string.</td></tr>

382

<tr><td valign="top"><tt>QString::SectionCaseInsensitiveSeps</tt></td><td align="center" valign="top"><tt>0x08</tt></td><td valign="top">Compare the separator case-insensitively.</td></tr>

383

</table>

384

The SectionFlags type is a typedef for <a href="qflags.html">QFlags</a><SectionFlag>. It stores an OR combination of SectionFlag values.

385

See also <a href="qstring.html#section">section</a>().

386

<h3 class="fn"><a name="SplitBehavior-enum"></a>enum QString::SplitBehavior</h3>

387

388

<tr><th width="60%">Constant</th><th width="40%">Value</th></tr>

389

<tr><td valign="top"><tt>QString::KeepEmptyParts</tt></td><td align="center" valign="top"><tt>0</tt></td></tr>

390

<tr><td valign="top"><tt>QString::SkipEmptyParts</tt></td><td align="center" valign="top"><tt>1</tt></td></tr>

391

</table>

392

<hr />

393

<h2>Member Function Documentation</h2>

394

<h3 class="fn"><a name="QString"></a>QString::QString ()</h3>

395

Constructs a null string. Null strings are also empty.

396

See also <a href="qstring.html#isEmpty">isEmpty</a>().

397

<h3 class="fn"><a name="QString-2"></a>QString::QString ( const <a href="qchar.html">QChar</a> * unicode, int size )</h3>

398

Constructs a string initialized with the first size characters of the <a href="qchar.html">QChar</a> array unicode.

399

<a href="qstring.html">QString</a> makes a deep copy of the string data.

400

<h3 class="fn"><a name="QString-3"></a>QString::QString ( <a href="qchar.html">QChar</a> ch )</h3>

401

Constructs a string of size 1 containing the character ch.

402

<h3 class="fn"><a name="QString-4"></a>QString::QString ( int size, <a href="qchar.html">QChar</a> ch )</h3>

403

Constructs a string of size size with every character set to ch.

404

See also <a href="qstring.html#fill">fill</a>().

405

<h3 class="fn"><a name="QString-5"></a>QString::QString ( const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

406

Constructs a copy of the Latin-1 string str.

407

See also <a href="qstring.html#fromLatin1">fromLatin1</a>().

408

<h3 class="fn"><a name="QString-6"></a>QString::QString ( const QString & other )</h3>

409

Constructs a copy of other.

410

This operation takes <a href="containers.html#constant-time">constant time</a>, because <a href="qstring.html">QString</a> is <a href="shclass.html#implicitly-shared">implicitly shared</a>. This makes returning a <a href="qstring.html">QString</a> from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes <a href="containers.html#linear-time">linear time</a>.

411

See also <a href="qstring.html#operator-eq">operator=</a>().

412

<h3 class="fn"><a name="QString-7"></a>QString::QString ( const char * str )</h3>

413

Constructs a string initialized with the ASCII string str. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

414

You can disable this constructor by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through <a href="qobject.html#tr">QObject::tr</a>(), for example.

415

See also <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>(), and <a href="qstring.html#fromUtf8">fromUtf8</a>().

416

<h3 class="fn"><a name="QString-8"></a>QString::QString ( const <a href="qbytearray.html">QByteArray</a> & ba )</h3>

417

Constructs a string initialized with the byte array ba. ba is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

418

419

<h3 class="fn"><a name="dtor.QString"></a>QString::~QString ()</h3>

420

Destroys the string.

421

<h3 class="fn"><a name="append"></a>QString & QString::append ( const QString & str )</h3>

422

Appends the string str onto the end of this string.

423

Example:

424

<pre>  QString x = "free";

425

QString y = "dom";

426

x.append(y);

427

// x == "freedom"</pre>

428

This is the same as insert(<a href="qstring.html#size">size</a>(), str).

429

This operation is typically very fast (<a href="containers.html#constant-time">constant time</a>), because <a href="qstring.html">QString</a> preallocates extra space at the end of the string data so it can grow without reallocating the entire string each time.

430

See also <a href="qstring.html#operator-2b-eq">operator+=</a>(), <a href="qstring.html#prepend">prepend</a>(), and <a href="qstring.html#insert">insert</a>().

431

<h3 class="fn"><a name="append-2"></a>QString & QString::append ( const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

432

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

433

Appends the Latin-1 string str to this string.

434

<h3 class="fn"><a name="append-3"></a>QString & QString::append ( const <a href="qbytearray.html">QByteArray</a> & ba )</h3>

435

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

436

Appends the byte array ba to this string. ba is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

437

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through <a href="qobject.html#tr">QObject::tr</a>(), for example.

438

<h3 class="fn"><a name="append-4"></a>QString & QString::append ( const char * str )</h3>

439

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

440

Appends the string str to this string. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

441

442

<h3 class="fn"><a name="append-5"></a>QString & QString::append ( <a href="qchar.html">QChar</a> ch )</h3>

443

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

444

Appends the character ch to this string.

445

<h3 class="fn"><a name="arg"></a>QString QString::arg ( const QString & a, int fieldWidth = 0, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

446

This function returns a copy of this string where a replaces the lowest numbered occurrence of <tt>%1</tt>, <tt>%2</tt>, ..., <tt>%9</tt>.

447

The fieldWidth value specifies the minimum amount of space that a is padded to and filled with the character fillChar. A positive value will produce right-aligned text, whereas a negative value will produce left-aligned text.

448

The following example shows how we could create a 'status' string when processing a list of files:

449

<pre>  QString status = QString("Processing file %1 of %2: %3")

450

.arg(i) // current file's number

451

.arg(total) // number of files to process

452

.arg(fileName); // current file's name</pre>

453

It is generally fine to use file names and numbers as we have done in the example above. But note that using arg() to construct natural language sentences does not usually translate well into other languages because sentence structure and word order often differ between languages.

454

If there is no place marker (<tt>%1</tt>, <tt>%2</tt>, etc.), a warning message is output and the result is undefined.

455

<h3 class="fn"><a name="arg-2"></a>QString QString::arg ( const QString & a1, const QString & a2 ) const</h3>

456

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

457

This is the same as str.arg(a1).arg(a2), except that the strings are replaced in one pass. This can make a difference if a1 contains e.g. <tt>%1</tt>:

458

<pre>  QString str = "%1 %2";

459

str.arg("%1f", "Hello"); // returns "%1f Hello"

460

str.arg("%1f").arg("Hello"); // returns "Hellof"</pre>

461

<h3 class="fn"><a name="arg-3"></a>QString QString::arg ( const QString & a1, const QString & a2, const QString & a3 ) const</h3>

462

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

463

This is the same as calling str.arg(a1).arg(a2).arg(a3), except that the strings are replaced in one pass.

464

<h3 class="fn"><a name="arg-4"></a>QString QString::arg ( const QString & a1, const QString & a2, const QString & a3, const QString & a4 ) const</h3>

465

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

466

This is the same as calling str.arg(a1).arg(a2).arg(a3).arg(a4), except that the strings are replaced in one pass.

467

<h3 class="fn"><a name="arg-5"></a>QString QString::arg ( int a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

468

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

469

a is expressed in base base, which is 10 by default and must be between 2 and 36.

470

The fieldWidth value specifies the minimum amount of space that a is padded to and filled with the character fillChar. A positive value will produce a right-aligned number, whereas a negative value will produce a left-aligned number.

471

The '%' can be followed by an 'L', in which case the sequence is replaced with a localized representation of a. The conversion uses the default locale, set by QLocale::setDefaultLocale(). If no default locale was specified, the "C" locale is used. The 'L' flag is ignored if base is not 10.

472

<pre>  QString str;

473

str = QString("Decimal 63 is %1 in hexadecimal")

474

.arg(63, 0, 16);

475

// str == "Decimal 63 is 3f in hexadecimal"

476

477

QLocale::setDefaultLocale(QLocale::English, QLocale::UnitedStates);

478

str = QString("%1 %L2 %L3")

479

.arg(12345)

480

.arg(12345)

481

.arg(12345, 0, 16);

482

// str == "12345 12,345 3039"</pre>

483

<h3 class="fn"><a name="arg-6"></a>QString QString::arg ( <a href="qtglobal.html#uint-typedef">uint</a> a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

484

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

485

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

486

<h3 class="fn"><a name="arg-7"></a>QString QString::arg ( long a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

487

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

488

489

a is expressed in base base, which is 10 by default and must be between 2 and 36.

490

The '%' can be followed by an 'L', in which case the sequence is replaced with a localized representation of a. The conversion uses the default locale. The default locale is determined from the system's locale settings at application startup. It can be changed using <a href="qlocale.html#setDefault">QLocale::setDefault</a>(). The 'L' flag is ignored if base is not 10.

491

<pre>  QString str;

492

str = QString( "Decimal 63 is %1 in hexadecimal" )

493

.arg( 63, 0, 16 );

494

// str == "Decimal 63 is 3f in hexadecimal"

495

496

QLocale::setDefault(QLocale::English, QLocale::UnitedStates);

497

str = QString( "%1 %L2 %L3" )

498

.arg( 12345 )

499

.arg( 12345 )

500

.arg( 12345, 0, 16 );

501

// str == "12345 12,345 3039"</pre>

502

<h3 class="fn"><a name="arg-8"></a>QString QString::arg ( <a href="qtglobal.html#ulong-typedef">ulong</a> a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

503

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

504

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

505

<h3 class="fn"><a name="arg-9"></a>QString QString::arg ( <a href="qtglobal.html#qlonglong-typedef">qlonglong</a> a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

506

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

507

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

508

<h3 class="fn"><a name="arg-10"></a>QString QString::arg ( <a href="qtglobal.html#qulonglong-typedef">qulonglong</a> a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

509

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

510

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

511

<h3 class="fn"><a name="arg-11"></a>QString QString::arg ( short a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

512

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

513

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

514

<h3 class="fn"><a name="arg-12"></a>QString QString::arg ( <a href="qtglobal.html#ushort-typedef">ushort</a> a, int fieldWidth = 0, int base = 10, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

515

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

516

base is the base to use when converting the integer a into a string. base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

517

<h3 class="fn"><a name="arg-13"></a>QString QString::arg ( <a href="qchar.html">QChar</a> a, int fieldWidth = 0, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

518

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

519

<h3 class="fn"><a name="arg-14"></a>QString QString::arg ( char a, int fieldWidth = 0, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

520

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

521

a is interpreded as a Latin-1 character.

522

<h3 class="fn"><a name="arg-15"></a>QString QString::arg ( double a, int fieldWidth = 0, char fmt = 'g', int prec = -1, const <a href="qchar.html">QChar</a> & fillChar = QLatin1Char( ' ' ) ) const</h3>

523

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

524

<a name="arg-formats"></a>Argument a is formatted according to the fmt format specified, which is 'g' by default and can be any of the following:

525

526

<tr valign="top" bgcolor="#a2c511"><th>Format</th><th>Meaning</th></tr>

527

<tr valign="top" bgcolor="#f0f0f0"><td><tt>e</tt></td><td>format as [-]9.9e[+|-]999</td></tr>

528

<tr valign="top" bgcolor="#e0e0e0"><td><tt>E</tt></td><td>format as [-]9.9E[+|-]999</td></tr>

529

<tr valign="top" bgcolor="#f0f0f0"><td><tt>f</tt></td><td>format as [-]9.9</td></tr>

530

<tr valign="top" bgcolor="#e0e0e0"><td><tt>g</tt></td><td>use <tt>e</tt> or <tt>f</tt> format, whichever is the most concise</td></tr>

531

<tr valign="top" bgcolor="#f0f0f0"><td><tt>G</tt></td><td>use <tt>E</tt> or <tt>f</tt> format, whichever is the most concise</td></tr>

532

</table>

533

With 'e', 'E', and 'f', prec is the number of digits after the decimal point. With 'g' and 'G', prec is the maximum number of significant digits (trailing zeroes are omitted).

534

<pre>  double d = 12.34;

535

QString str = QString("delta: %1").arg(d, 0, 'E', 3);

536

// str == "delta: 1.234E+01"</pre>

537

538

<h3 class="fn"><a name="at"></a>const <a href="qchar.html">QChar</a> QString::at ( int i ) const</h3>

539

Returns the character at index position i in the string.

540

i must be a valid index position in the string (i.e., 0 <= i < <a href="qstring.html#size">size</a>()).

541

See also <a href="qstring.html#operator-5b-5d">operator[]</a>().

542

<h3 class="fn"><a name="capacity"></a>int QString::capacity () const</h3>

543

Returns the maximum number of characters that can be stored in the string without forcing a reallocation.

544

The sole purpose of this function is to provide a means of fine tuning <a href="qstring.html">QString</a>'s memory usage. In general, you will rarely ever need to call this function. If you want to know how many characters are in the string, call <a href="qstring.html#size">size</a>().

545

See also <a href="qstring.html#reserve">reserve</a>() and <a href="qstring.html#squeeze">squeeze</a>().

546

<h3 class="fn"><a name="chop"></a>void QString::chop ( int n )</h3>

547

Removes n characters from the end of the string.

548

If n is greater than <a href="qstring.html#size">size</a>(), the result is an empty string.

549

Example:

550

<pre>  QString str("LOGOUT\r\n");

551

str.chop(2);

552

// str == "LOGOUT"</pre>

553

If you want to remove characters from the beginning of the string, use <a href="qstring.html#remove">remove</a>() instead.

554

See also <a href="qstring.html#truncate">truncate</a>(), <a href="qstring.html#resize">resize</a>(), and <a href="qstring.html#remove">remove</a>().

555

<h3 class="fn"><a name="clear"></a>void QString::clear ()</h3>

556

Clears the contents of the string and makes it empty.

557

See also <a href="qstring.html#resize">resize</a>() and <a href="qstring.html#isEmpty">isEmpty</a>().

558

<h3 class="fn"><a name="compare"></a>int QString::compare ( const QString & s1, const QString & s2 )  <tt> [static]</tt></h3>

559

Lexically compares s1 with s2 and returns an integer less than, equal to, or greater than zero if s1 is less than, equal to, or greater than s2.

560

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-visible strings with <a href="qstring.html#localeAwareCompare">localeAwareCompare</a>().

561

<pre>  int x = QString::compare("auto", "auto"); // x == 0

562

int y = QString::compare("auto", "car"); // y < 0

563

int z = QString::compare("car", "auto"); // z > 0</pre>

564

See also <a href="qstring.html#localeAwareCompare">localeAwareCompare</a>(), <a href="qstring.html#operator-eq-eq">operator==</a>(), <a href="qstring.html#operator-lt">operator<</a>(), and <a href="qstring.html#operator-gt">operator></a>().

565

<h3 class="fn"><a name="compare-2"></a>int QString::compare ( const QString & other ) const</h3>

566

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

567

Same as compare(*this, other).

568

<h3 class="fn"><a name="constData"></a>const <a href="qchar.html">QChar</a> * QString::constData () const</h3>

569

Returns a pointer to the data stored in the <a href="qstring.html">QString</a>. The pointer can be used to access the characters that compose the string. For convenience, the data is '\0'-terminated.

570

The pointer remains valid as long as the string isn't modified.

571

See also <a href="qstring.html#data">data</a>() and <a href="qstring.html#operator-5b-5d">operator[]</a>().

572

<h3 class="fn"><a name="contains"></a>bool QString::contains ( const QString & str, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

573

Returns true if this string contains an occurrence of the string str; otherwise returns false.

574

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

575

Example:

576

<pre>  QString str = "Peter Pan";

577

str.contains("peter", Qt::CaseInsensitive); // returns true</pre>

578

See also <a href="qstring.html#indexOf">indexOf</a>() and <a href="qstring.html#count">count</a>().

579

<h3 class="fn"><a name="contains-4"></a>bool QString::contains ( <a href="qchar.html">QChar</a> ch, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

580

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

581

Returns true if this string contains an occurrence of the character ch; otherwise returns false.

582

<h3 class="fn"><a name="contains-5"></a>bool QString::contains ( const <a href="qregexp.html">QRegExp</a> & rx ) const</h3>

583

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

584

Returns true if the regular expression rx matches somewhere in this string; otherwise returns false.

585

<h3 class="fn"><a name="count"></a>int QString::count ( const QString & str, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

586

Returns the number of (potentially overlapping) occurrences of the string str in this string.

587

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

588

See also <a href="qstring.html#contains">contains</a>() and <a href="qstring.html#indexOf">indexOf</a>().

589

<h3 class="fn"><a name="count-2"></a>int QString::count ( <a href="qchar.html">QChar</a> ch, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

590

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

591

Returns the number of occurrences of character ch in the string.

592

<h3 class="fn"><a name="count-3"></a>int QString::count ( const <a href="qregexp.html">QRegExp</a> & rx ) const</h3>

593

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

594

Returns the number of times the regular expression rx matches in the string.

595

This function counts overlapping matches, so in the example below, there are four instances of "ana" or "ama":

596

<pre>  QString str = "banana and panama";

597

str.contains(QRegExp("a[nm]a")); // returns 4</pre>

598

<h3 class="fn"><a name="count-4"></a>int QString::count () const</h3>

599

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

600

Same as <a href="qstring.html#size">size</a>().

601

<h3 class="fn"><a name="data"></a><a href="qchar.html">QChar</a> * QString::data ()</h3>

602

Returns a pointer to the data stored in the <a href="qstring.html">QString</a>. The pointer can be used to access and modify the characters that compose the string. For convenience, the data is '\0'-terminated.

603

The pointer remains valid as long as the string isn't modified by other means.

604

Example:

605

<pre>  QString str = "Hello world";

606

QChar *data = ba.data();

607

while (*data) {

608

cout << "[" + data->unicode() + "]" << endl;

609

++data;

610

}</pre>

611

See also <a href="qstring.html#constData">constData</a>() and <a href="qstring.html#operator-5b-5d">operator[]</a>().

612

<h3 class="fn"><a name="data-2"></a>const <a href="qchar.html">QChar</a> * QString::data () const</h3>

613

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

614

<h3 class="fn"><a name="endsWith"></a>bool QString::endsWith ( const QString & s, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

615

Returns true if the string ends with s; otherwise returns false.

616

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

617

<pre>  QString str = "Bananas";

618

str.endsWith("anas"); // returns true

619

str.endsWith("pple"); // returns false</pre>

620

See also <a href="qstring.html#startsWith">startsWith</a>().

621

<h3 class="fn"><a name="endsWith-3"></a>bool QString::endsWith ( const <a href="qlatin1string.html">QLatin1String</a> & s, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

622

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

623

<h3 class="fn"><a name="endsWith-4"></a>bool QString::endsWith ( const <a href="qchar.html">QChar</a> & c, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

624

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

625

<h3 class="fn"><a name="fill"></a>QString & QString::fill ( <a href="qchar.html">QChar</a> ch, int size = -1 )</h3>

626

Sets every character in the string to character ch. If size is different from -1 (the default), the string is resized to size beforehand.

627

Example:

628

<pre>  QString str = "Berlin";

629

str.fill("z");

630

// str == "zzzzzz"

631

632

str.fill("A", 2);

633

// str == "AA"</pre>

634

See also <a href="qstring.html#resize">resize</a>().

635

<h3 class="fn"><a name="fromAscii"></a>QString QString::fromAscii ( const char * str, int size = -1 )  <tt> [static]</tt></h3>

636

Returns a <a href="qstring.html">QString</a> initialized with the first size characters of the 8-bit ASCII string str.

637

If size is -1 (the default), it is taken to be qstrlen(str).

638

If a codec has been set using <a href="qtextcodec.html#setCodecForCStrings">QTextCodec::setCodecForCStrings</a>(), it is used to convert str to Unicode; otherwise this function does the same as <a href="qstring.html#fromLatin1">fromLatin1</a>().

639

See also <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#fromUtf8">fromUtf8</a>(), and <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>().

640

<h3 class="fn"><a name="fromLatin1"></a>QString QString::fromLatin1 ( const char * str, int size = -1 )  <tt> [static]</tt></h3>

641

Returns a <a href="qstring.html">QString</a> initialized with the first size characters of the Latin-1 string str.

642

If size is -1 (the default), it is taken to be qstrlen(str).

643

See also <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromUtf8">fromUtf8</a>(), and <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>().

644

<h3 class="fn"><a name="fromLocal8Bit"></a>QString QString::fromLocal8Bit ( const char * str, int size = -1 )  <tt> [static]</tt></h3>

645

Returns a <a href="qstring.html">QString</a> initialized with the first size characters of the 8-bit string str.

646

If size is -1 (the default), it is taken to be qstrlen(str).

647

<a href="qtextcodec.html#codecForLocale">QTextCodec::codecForLocale</a>() is used to perform the conversion from Unicode.

648

See also <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>(), <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), and <a href="qstring.html#fromUtf8">fromUtf8</a>().

649

<h3 class="fn"><a name="fromRawData"></a>QString QString::fromRawData ( const <a href="qchar.html">QChar</a> * unicode, int size )  <tt> [static]</tt></h3>

650

Constructs a <a href="qstring.html">QString</a> that uses the first size Unicode characters in the array unicode. The data in unicode is not copied. The caller must be able to guarantee that unicode will not be deleted or modified as long as the <a href="qstring.html">QString</a> (or an unmodified copy of it) exists.

651

Any attempts to modify the <a href="qstring.html">QString</a> or copies of it will cause it to create a deep copy of the data, ensuring that the raw data isn't modified.

652

Here's an example of how we can use a <a href="qregexp.html">QRegExp</a> on raw data in memory without requiring to copy the data into a <a href="qstring.html">QString</a>:

653

<pre>  static const QChar unicode[] = {

654

0x005A, 0x007F, 0x00A4, 0x0060, 0x1009, 0x0020,

655

...

656

0x0020

657

};

658

int size = sizeof(unicode) / sizeof(QChar);

659

660

QString str = QString::fromRawData(unicode, size);

661

if (str.contains(QRegExp(pattern)))

662

...</pre>

663

Warning: A string created with fromRawData() is not '\0'-terminated, unless the raw data contains a '\0' character at position size. This means <a href="qstring.html#unicode">unicode</a>() will not return a '\0'-terminated string (although <a href="qstring.html#utf16">utf16</a>() does, at the cost of copying the raw data).

664

See also <a href="qstring.html#fromUtf16">fromUtf16</a>().

665

<h3 class="fn"><a name="fromStdString"></a>QString QString::fromStdString ( const std::string & str )  <tt> [static]</tt></h3>

666

Returns a copy of str. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

667

This constructor is only available if Qt is configured with STL compabitility enabled.

668

669

<h3 class="fn"><a name="fromStdWString"></a>QString QString::fromStdWString ( const std::wstring & str )  <tt> [static]</tt></h3>

670

Returns a copy of str. str is assumed to be encoded in utf16 if the size of wchar_t is 2 bytes (e.g. on windows) and ucs4 if the size of wchar_t is 4 bytes (most Unix systems).

671

This constructor is only available if Qt is configured with STL compabitility enabled.

672

See also <a href="qstring.html#fromUtf16">fromUtf16</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>(), and <a href="qstring.html#fromUtf8">fromUtf8</a>().

673

<h3 class="fn"><a name="fromUtf8"></a>QString QString::fromUtf8 ( const char * str, int size = -1 )  <tt> [static]</tt></h3>

674

Returns a <a href="qstring.html">QString</a> initialized with the first size bytes of the UTF-8 string str.

675

If size is -1 (the default), it is taken to be qstrlen(str).

676

See also <a href="qstring.html#toUtf8">toUtf8</a>(), <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#fromLatin1">fromLatin1</a>(), and <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>().

677

<h3 class="fn"><a name="fromUtf16"></a>QString QString::fromUtf16 ( const <a href="qtglobal.html#ushort-typedef">ushort</a> * unicode, int size = -1 )  <tt> [static]</tt></h3>

678

Returns a <a href="qstring.html">QString</a> initialized with the first size characters of the Unicode string unicode (ISO-10646-UTF-16 encoded).

679

If size is -1 (the default), unicode must be terminated with a 0.

680

<a href="qstring.html">QString</a> makes a deep copy of the Unicode data.

681

See also <a href="qstring.html#utf16">utf16</a>() and <a href="qstring.html#setUtf16">setUtf16</a>().

682

<h3 class="fn"><a name="indexOf"></a>int QString::indexOf ( const QString & str, int from = 0, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

683

Returns the index position of the first occurrence of the string str in this string, searching forward from index position from. Returns -1 if str is not found.

684

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

685

Example:

686

<pre>  QString x = "sticky question";

687

QString y = "sti";

688

x.indexOf(y); // returns 0

689

x.indexOf(y, 1); // returns 10

690

x.indexOf(y, 10); // returns 10

691

x.indexOf(y, 11); // returns -1</pre>

692

If from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.

693

See also <a href="qstring.html#lastIndexOf">lastIndexOf</a>(), <a href="qstring.html#contains">contains</a>(), and <a href="qstring.html#count">count</a>().

694

<h3 class="fn"><a name="indexOf-2"></a>int QString::indexOf ( <a href="qchar.html">QChar</a> ch, int from = 0, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

695

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

696

Returns the index position of the first occurrence of the character ch in the string, searching forward from index position from. Returns -1 if ch could not be found.

697

<h3 class="fn"><a name="indexOf-3"></a>int QString::indexOf ( const <a href="qregexp.html">QRegExp</a> & rx, int from = 0 ) const</h3>

698

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

699

Returns the index position of the first match of the regular expression rx in the string, searching forward from index position from. Returns -1 if rx didn't match anywhere.

700

Example:

701

<pre>  QString str = "the minimum";

702

str.indexOf(QRegExp("m[aeiou]"), 0); // returns 4</pre>

703

<h3 class="fn"><a name="insert"></a>QString & QString::insert ( int i, const QString & str )</h3>

704

Inserts the string str at index position i and returns a reference to this string.

705

Example:

706

<pre>  QString str = "Meal";

707

str.insert(1, QString("ontr"));

708

// str == "Montreal"</pre>

709

If i is greater than <a href="qstring.html#size">size</a>(), the array is first extended using <a href="qstring.html#resize">resize</a>().

710

See also <a href="qstring.html#append">append</a>(), <a href="qstring.html#prepend">prepend</a>(), <a href="qstring.html#replace">replace</a>(), and <a href="qstring.html#remove">remove</a>().

711

<h3 class="fn"><a name="insert-2"></a>QString & QString::insert ( int i, const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

712

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

713

Inserts the Latin-1 string str at index position i.

714

<h3 class="fn"><a name="insert-3"></a>QString & QString::insert ( int i, const <a href="qchar.html">QChar</a> * unicode, int size )</h3>

715

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

716

Inserts the first size characters of the <a href="qchar.html">QChar</a> array unicode at index position i in the string.

717

<h3 class="fn"><a name="insert-4"></a>QString & QString::insert ( int i, <a href="qchar.html">QChar</a> ch )</h3>

718

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

719

Inserts ch at index position i in the string.

720

<h3 class="fn"><a name="isEmpty"></a>bool QString::isEmpty () const</h3>

721

Returns true if the string has no characters; otherwise returns false.

722

Example:

723

<pre>  QString().isEmpty(); // returns true

724

QString("").isEmpty(); // returns true

725

QString("x").isEmpty(); // returns false

726

QString("abc").isEmpty(); // returns false</pre>

727

See also <a href="qstring.html#size">size</a>().

728

<h3 class="fn"><a name="isNull"></a>bool QString::isNull () const</h3>

729

Returns true if this string is null; otherwise returns false.

730

Example:

731

<pre>  QString().isNull(); // returns true

732

QString("").isNull(); // returns false

733

QString("abc").isNull(); // returns false</pre>

734

Qt makes a distinction between null strings and empty strings for historical reasons. For most applications, what matters is whether or not a string contains any data, and this can be determined using <a href="qstring.html#isEmpty">isEmpty</a>().

735

See also <a href="qstring.html#isEmpty">isEmpty</a>().

736

<h3 class="fn"><a name="lastIndexOf"></a>int QString::lastIndexOf ( const QString & str, int from = -1, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

737

Returns the index position of the last occurrence of the string str in this string, searching backward from index position from. If from is -1 (the default), the search starts at the last character; if from is -2, at the next to last character and so on. Returns -1 if str is not found.

738

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

739

Example:

740

<pre>  QString x = "crazy azimuths";

741

QString y = "az";

742

x.lastIndexOf(y); // returns 6

743

x.lastIndexOf(y, 6); // returns 6

744

x.lastIndexOf(y, 5); // returns 2

745

x.lastIndexOf(y, 1); // returns -1</pre>

746

See also <a href="qstring.html#indexOf">indexOf</a>(), <a href="qstring.html#contains">contains</a>(), and <a href="qstring.html#count">count</a>().

747

<h3 class="fn"><a name="lastIndexOf-2"></a>int QString::lastIndexOf ( <a href="qchar.html">QChar</a> ch, int from = -1, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

748

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

749

Returns the index position of the last occurrence of the character ch, searching backward from position from.

750

<h3 class="fn"><a name="lastIndexOf-3"></a>int QString::lastIndexOf ( const <a href="qregexp.html">QRegExp</a> & rx, int from = -1 ) const</h3>

751

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

752

Returns the index position of the last match of the regular expression rx in the string, searching backward from index position from. Returns -1 if rx didn't match anywhere.

753

Example:

754

<pre>  QString str = "the minimum";

755

str.lastIndexOf(QRegExp("m[aeiou]")); // returns 8</pre>

756

<h3 class="fn"><a name="left"></a>QString QString::left ( int len ) const</h3>

757

Returns a substring that contains the len leftmost characters of the string.

758

The entire string is returned if len is greater than <a href="qstring.html#size">size</a>() or less than zero.

759

<pre>  QString x = "Pineapple";

760

QString y = x.left(4); // y == "Pine"</pre>

761

See also <a href="qstring.html#right">right</a>(), <a href="qstring.html#mid">mid</a>(), and <a href="qstring.html#startsWith">startsWith</a>().

762

<h3 class="fn"><a name="leftJustified"></a>QString QString::leftJustified ( int width, <a href="qchar.html">QChar</a> fill = QLatin1Char( ' ' ), bool truncate = false ) const</h3>

763

Returns a string of <a href="qstring.html#size">size</a>() width that contains this string padded by the fill character.

764

If truncate is false and the <a href="qstring.html#size">size</a>() of the string is more than width, then the returned string is a copy of the string.

765

If truncate is true and the <a href="qstring.html#size">size</a>() of the string is more than width, then any characters in a copy of the string after position width are removed, and the copy is returned.

766

<pre>  QString s = "apple";

767

QString t = s.leftJustified(8, '.'); // t == "apple..."</pre>

768

See also <a href="qstring.html#rightJustified">rightJustified</a>().

769

<h3 class="fn"><a name="length"></a>int QString::length () const</h3>

770

Same as <a href="qstring.html#size">size</a>().

771

<h3 class="fn"><a name="localeAwareCompare"></a>int QString::localeAwareCompare ( const QString & s1, const QString & s2 )  <tt> [static]</tt></h3>

772

Compares s1 with s2 and returns an integer less than, equal to, or greater than zero if s1 is less than, equal to, or greater than s2.

773

The comparison is performed in a locale- and also platform-dependent manner. Use this function to present sorted lists of strings to the user.

774

See also <a href="qstring.html#compare">compare</a>() and <a href="qtextcodec-qt3.html#locale">QTextCodec::locale</a>().

775

<h3 class="fn"><a name="localeAwareCompare-2"></a>int QString::localeAwareCompare ( const QString & other ) const</h3>

776

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

777

Same as localeAwareCompare(*this, other).

778

<h3 class="fn"><a name="mid"></a>QString QString::mid ( int i, int len = -1 ) const</h3>

779

Returns a string that contains the len characters of this string, starting at position i.

780

Returns an empty string if index i exceeds the length of the string. If there are less than len characters available in the string starting at position i, or if len is -1 (the default), the function returns all characters that are available from position i.

781

Example:

782

<pre>  QString x = "Nine pineapples";

783

QString y = x.mid(5, 4); // y == "pine"

784

QString z = x.mid(5); // z == "pineapples"</pre>

785

See also <a href="qstring.html#left">left</a>() and <a href="qstring.html#right">right</a>().

786

<h3 class="fn"><a name="normalized"></a>QString QString::normalized ( <a href="qstring.html#NormalizationForm-enum">NormalizationForm</a> form ) const</h3>

787

Returns the string in the given Unicode normalization form.

788

<h3 class="fn"><a name="normalized-2"></a>QString QString::normalized ( <a href="qstring.html#NormalizationForm-enum">NormalizationForm</a> form, <a href="qchar.html#UnicodeVersion-enum">QChar::UnicodeVersion</a> version ) const</h3>

789

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

790

Returns the string in the given Unicode normalization form, according to the given version of the Unicode standard.

791

<h3 class="fn"><a name="number"></a>QString QString::number ( long n, int base = 10 )  <tt> [static]</tt></h3>

792

Returns a string equivalent of the number n to base base, which is 10 by default and must be between 2 and 36.

793

<pre>  long a = 63;

794

QString str = QString::number(a, 16); // str == "3f"

795

QString str = QString::number(a, 16).upper(); // str == "3F"</pre>

796

See also <a href="qstring.html#setNum">setNum</a>().

797

<h3 class="fn"><a name="number-2"></a>QString QString::number ( <a href="qtglobal.html#ulong-typedef">ulong</a> n, int base = 10 )  <tt> [static]</tt></h3>

798

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

799

<h3 class="fn"><a name="number-3"></a>QString QString::number ( int n, int base = 10 )  <tt> [static]</tt></h3>

800

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

801

<h3 class="fn"><a name="number-4"></a>QString QString::number ( <a href="qtglobal.html#uint-typedef">uint</a> n, int base = 10 )  <tt> [static]</tt></h3>

802

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

803

<h3 class="fn"><a name="number-5"></a>QString QString::number ( <a href="qtglobal.html#qlonglong-typedef">qlonglong</a> n, int base = 10 )  <tt> [static]</tt></h3>

804

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

805

<h3 class="fn"><a name="number-6"></a>QString QString::number ( <a href="qtglobal.html#qulonglong-typedef">qulonglong</a> n, int base = 10 )  <tt> [static]</tt></h3>

806

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

807

<h3 class="fn"><a name="number-7"></a>QString QString::number ( double n, char f = 'g', int prec = 6 )  <tt> [static]</tt></h3>

808

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

809

Argument n is formatted according to the format f, and the precision prec. The format f can be 'f', 'F', 'e', 'E', 'g' or 'G'. See arg() for an explanation of the formats.

810

See also <a href="qstring.html#setNum">setNum</a>().

811

<h3 class="fn"><a name="prepend"></a>QString & QString::prepend ( const QString & str )</h3>

812

Prepends the string str to the beginning of this string and returns a reference to this string.

813

Example:

814

<pre>  QString x = "ship";

815

QString y = "air";

816

x.prepend(y);

817

// x == "airship"</pre>

818

See also <a href="qstring.html#append">append</a>() and <a href="qstring.html#insert">insert</a>().

819

<h3 class="fn"><a name="prepend-2"></a>QString & QString::prepend ( const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

820

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

821

Prepends the Latin-1 string str to this string.

822

<h3 class="fn"><a name="prepend-3"></a>QString & QString::prepend ( const <a href="qbytearray.html">QByteArray</a> & ba )</h3>

823

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

824

Prepends the byte array ba to this string. ba is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

825

826

<h3 class="fn"><a name="prepend-4"></a>QString & QString::prepend ( const char * str )</h3>

827

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

828

Prepends the string str to this string. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

829

830

<h3 class="fn"><a name="prepend-5"></a>QString & QString::prepend ( <a href="qchar.html">QChar</a> ch )</h3>

831

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

832

Prepends the character ch to this string.

833

<h3 class="fn"><a name="push_back"></a>void QString::push_back ( const QString & other )</h3>

834

This function is provided for STL compatibility. It is equivalent to append(other).

835

<h3 class="fn"><a name="push_back-2"></a>void QString::push_back ( <a href="qchar.html">QChar</a> ch )</h3>

836

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

837

Same as append(ch).

838

<h3 class="fn"><a name="push_front"></a>void QString::push_front ( const QString & other )</h3>

839

This function is provided for STL compatibility. It is equivalent to prepend(other).

840

<h3 class="fn"><a name="push_front-2"></a>void QString::push_front ( <a href="qchar.html">QChar</a> ch )</h3>

841

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

842

Same as prepend(ch).

843

<h3 class="fn"><a name="remove"></a>QString & QString::remove ( int pos, int len )</h3>

844

Removes len characters from the string, starting at index position pos, and returns a reference to the string.

845

If pos is within the string, but pos + len is beyond the end of the string, the string is truncated at position pos.

846

<pre>  QString str = "Montreal";

847

str.remove(1, 4);

848

// str == "Meal"</pre>

849

See also <a href="qstring.html#insert">insert</a>() and <a href="qstring.html#replace">replace</a>().

850

<h3 class="fn"><a name="remove-4"></a>QString & QString::remove ( const QString & str, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive )</h3>

851

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

852

Removes every occurrence of str in this string. Returns a reference to this string.

853

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

854

This is the same as replace(str, "", cs).

855

<h3 class="fn"><a name="remove-5"></a>QString & QString::remove ( <a href="qchar.html">QChar</a> ch, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive )</h3>

856

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

857

Removes every occurrence of the character ch in this string, and returns a reference to this string.

858

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

859

Example:

860

<pre>  QString str = "Ali Baba";

861

str.remove(QChar('a'), Qt::CaseInsensitive);

862

// str == "li Bb"</pre>

863

This is the same as replace(ch, "", cs).

864

<h3 class="fn"><a name="remove-6"></a>QString & QString::remove ( const <a href="qregexp.html">QRegExp</a> & rx )</h3>

865

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

866

Removes every occurrence of the regular expression rx in the string, and returns a reference to the string. For example:

867

<pre>  QString str = "Telephone";

868

str.remove(QRegExp("[aeiou]."));

869

// str == "The"</pre>

870

See also <a href="qstring.html#indexOf">indexOf</a>(), <a href="qstring.html#lastIndexOf">lastIndexOf</a>(), and <a href="qstring.html#replace">replace</a>().

871

<h3 class="fn"><a name="replace"></a>QString & QString::replace ( int pos, int len, const QString & after )</h3>

872

Replaces len characters from index position pos with the string after, and returns a reference to this string.

873

Example:

874

<pre>  QString x = "Say yes!";

875

QString y = "no";

876

x.replace(4, 3, y);

877

// x == "Say no!"</pre>

878

See also <a href="qstring.html#insert">insert</a>() and <a href="qstring.html#remove">remove</a>().

879

<h3 class="fn"><a name="replace-6"></a>QString & QString::replace ( int pos, int len, const <a href="qchar.html">QChar</a> * unicode, int size )</h3>

880

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

881

Replaces len characters from index position pos with the first size characters of the <a href="qchar.html">QChar</a> array unicode.

882

<h3 class="fn"><a name="replace-7"></a>QString & QString::replace ( int pos, int len, <a href="qchar.html">QChar</a> after )</h3>

883

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

884

Replaces len characters from index position pos with the character after.

885

<h3 class="fn"><a name="replace-8"></a>QString & QString::replace ( const QString & before, const QString & after, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive )</h3>

886

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

887

Replaces every occurrence of the string before with the string after.

888

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

889

Example:

890

<pre>  QString str = "colour behaviour flavour neighbour";

891

str.replace(QString("ou"), QString("o"));

892

// str == "color behavior flavor neighbor"</pre>

893

<h3 class="fn"><a name="replace-9"></a>QString & QString::replace ( <a href="qchar.html">QChar</a> ch, const QString & after, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive )</h3>

894

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

895

Replaces every occurrence of the character ch in the string with after. Returns a reference to the string.

896

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

897

<h3 class="fn"><a name="replace-10"></a>QString & QString::replace ( <a href="qchar.html">QChar</a> before, <a href="qchar.html">QChar</a> after, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive )</h3>

898

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

899

Replaces every occurrence of the character before with the character after. Returns a reference to the string.

900

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

901

<h3 class="fn"><a name="replace-11"></a>QString & QString::replace ( const <a href="qregexp.html">QRegExp</a> & rx, const QString & after )</h3>

902

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

903

Replaces every occurrence of the regular expression rx in the string with after. Returns a reference to the string. For example:

904

<pre>  QString str = "Banana";

905

str.replace(QRegExp("a[mn]"), "ox");

906

// str == "Boxoxa"</pre>

907

For regular expressions containing <a href="qregexp.html#capturing-parentheses">capturing parentheses</a>, occurrences of \1, \2, ..., in after are replaced with rx.cap(1), cap(2), ...

908

<pre>  QString str = "A bon mot.";

909

str.replace(QRegExp("([^<]*)"), "\\emph{\\1}");

910

// str == "A \\emph{bon mot}."</pre>

911

See also <a href="qstring.html#indexOf">indexOf</a>(), <a href="qstring.html#lastIndexOf">lastIndexOf</a>(), <a href="qstring.html#remove">remove</a>(), and <a href="qregexp.html#cap">QRegExp::cap</a>().

912

<h3 class="fn"><a name="reserve"></a>void QString::reserve ( int size )</h3>

913

Attempts to allocate memory for at least size characters. If you know in advance how large the string will be, you can call this function, and if you resize the string often you are likely to get better performance. If size is an underestimate, the worst that will happen is that the <a href="qstring.html">QString</a> will be a bit slower.

914

The sole purpose of this function is to provide a means of fine tuning <a href="qstring.html">QString</a>'s memory usage. In general, you will rarely ever need to call this function. If you want to change the size of the string, call <a href="qstring.html#resize">resize</a>().

915

This function is useful for code that needs to build up a long string and wants to avoid repeated reallocation. In this example, we want to add to the string until some condition is true, and we're fairly sure that size is large enough to make a call to reserve() worthwhile:

916

<pre>  QString result;

917

int len = 0;

918

result.reserve(maxSize);

919

while (...) {

920

result[len++] = getNextChar(); // fill part of the space

921

}

922

result.squeeze();</pre>

923

See also <a href="qstring.html#squeeze">squeeze</a>() and <a href="qstring.html#capacity">capacity</a>().

924

<h3 class="fn"><a name="resize"></a>void QString::resize ( int size )</h3>

925

Sets the size of the string to size characters.

926

If size is greater than the current size, the string is extended to make it size characters long with the extra characters added to the end. The new characters are uninitialized.

927

If size is less than the current size, characters are removed from the end.

928

Example:

929

<pre>  QString str = "Hello world";

930

str.resize(5);

931

// str == "Hello"

932

933

str.resize(8);

934

// str == "Hello???" (where ? stands for any character)</pre>

935

If you want to append a certain number of identical characters to the string, use operator+=() as follows rather than resize():

936

<pre>  QString str = "Hello";

937

str += QString(10, 'X');

938

// str == "HelloXXXXXXXXXX"</pre>

939

If you want to expand the string so that it reaches a certain width and fill the new positions with a particular character, use <a href="qstring.html#leftJustified">leftJustified</a>():

940

<pre>  QString str = "Hello";

941

str = str.leftJustified(10, ' ');

942

// str == "Hello "</pre>

943

See also <a href="qstring.html#truncate">truncate</a>() and <a href="qstring.html#reserve">reserve</a>().

944

<h3 class="fn"><a name="right"></a>QString QString::right ( int len ) const</h3>

945

Returns a substring that contains the len rightmost characters of the string.

946

The entire string is returned if len is greater than <a href="qstring.html#size">size</a>() or less than zero.

947

<pre>  QString x = "Pineapple";

948

QString y = x.right(5); // y == "apple"</pre>

949

See also <a href="qstring.html#left">left</a>(), <a href="qstring.html#mid">mid</a>(), and <a href="qstring.html#endsWith">endsWith</a>().

950

<h3 class="fn"><a name="rightJustified"></a>QString QString::rightJustified ( int width, <a href="qchar.html">QChar</a> fill = QLatin1Char( ' ' ), bool truncate = false ) const</h3>

951

Returns a string of <a href="qstring.html#size">size</a>() width that contains the fill character followed by the string.

952

If truncate is false and the <a href="qstring.html#size">size</a>() of the string is more than width, then the returned string is a copy of the string.

953

If truncate is true and the <a href="qstring.html#size">size</a>() of the string is more than width, then the resulting string is truncated at position width.

954

<pre>  QString str = "apple";

955

str = str.rightJustified(8, '.');

956

// str == "...apple"</pre>

957

See also <a href="qstring.html#leftJustified">leftJustified</a>().

958

<h3 class="fn"><a name="section"></a>QString QString::section ( <a href="qchar.html">QChar</a> sep, int start, int end = -1, <a href="qstring.html#SectionFlag-enum">SectionFlags</a> flags = SectionDefault ) const</h3>

959

This function returns a section of the string.

960

This string is treated as a sequence of fields separated by the character, sep. The returned string consists of the fields from position start to position end inclusive. If end is not specified, all fields from position start to the end of the string are included. Fields are numbered 0, 1, 2, etc., counting from the left, and -1, -2, etc., counting from right to left.

961

The flags argument can be used to affect some aspects of the function's behavior, e.g. whether to be case sensitive, whether to skip empty fields and how to deal with leading and trailing separators; see <a href="qstring.html#SectionFlag-enum">SectionFlags</a>.

962

<pre>  QString csv = "forename,middlename,surname,phone";

963

QString str = csv.section(',', 2, 2); // str == "surname"

964

965

QString path = "/usr/local/bin/myapp"; // First field is empty

966

QString str = path.section('/', 3, 4); // str == "bin/myapp"

967

QString str = path.section('/', 3, 3, SectionSkipEmpty); // str == "myapp"</pre>

968

If start or end is negative, we count fields from the right of the string, the right-most field being -1, the one from right-most field being -2, and so on.

969

<pre>  QString csv = "forename,middlename,surname,phone";

970

QString str = csv.section(',', -3, -2); // str == "middlename,surname"

971

972

QString path = "/usr/local/bin/myapp"; // First field is empty

973

QString str = path.section('/', -1); // str == "myapp"</pre>

974

See also <a href="qstring.html#split">split</a>().

975

<h3 class="fn"><a name="section-2"></a>QString QString::section ( const QString & sep, int start, int end = -1, <a href="qstring.html#SectionFlag-enum">SectionFlags</a> flags = SectionDefault ) const</h3>

976

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

977

<pre>  QString data = "forename**middlename**surname**phone";

978

QString str = data.section("**", 2, 2); // str == "surname"</pre>

979

<pre>  QString data = "forename**middlename**surname**phone";

980

QString str = data.section("**", -3, -2); // str == "middlename**surname"</pre>

981

See also <a href="qstring.html#split">split</a>().

982

<h3 class="fn"><a name="section-3"></a>QString QString::section ( const <a href="qregexp.html">QRegExp</a> & reg, int start, int end = -1, <a href="qstring.html#SectionFlag-enum">SectionFlags</a> flags = SectionDefault ) const</h3>

983

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

984

This string is treated as a sequence of fields separated by the regular expression, reg.

985

<pre>  QString line = "forename\tmiddlename surname \t \t phone";

986

QRegExp sep("\\s+");

987

QString s = line.section(sep, 2, 2); // s == "surname"</pre>

988

<pre>  QString line = "forename\tmiddlename surname \t \t phone";

989

QRegExp sep("\\s+");

990

QString s = line.section(sep, -3, -2); // s == "middlename surname"</pre>

991

Warning: Using this <a href="qregexp.html">QRegExp</a> version is much more expensive than the overloaded string and character versions.

992

See also <a href="qstring.html#split">split</a>() and <a href="qstring.html#simplified">simplified</a>().

993

<h3 class="fn"><a name="setNum"></a>QString & QString::setNum ( int n, int base = 10 )</h3>

994

Sets the string to the printed value of n in base base and returns a reference to the string.

995

The base is 10 by default and must be between 2 and 36.

996

<pre>  QString str;

997

str.setNum(1234); // str == "1234"</pre>

998

<h3 class="fn"><a name="setNum-2"></a>QString & QString::setNum ( <a href="qtglobal.html#uint-typedef">uint</a> n, int base = 10 )</h3>

999

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1000

<h3 class="fn"><a name="setNum-3"></a>QString & QString::setNum ( long n, int base = 10 )</h3>

1001

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1002

<h3 class="fn"><a name="setNum-4"></a>QString & QString::setNum ( <a href="qtglobal.html#ulong-typedef">ulong</a> n, int base = 10 )</h3>

1003

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1004

<h3 class="fn"><a name="setNum-5"></a>QString & QString::setNum ( <a href="qtglobal.html#qlonglong-typedef">qlonglong</a> n, int base = 10 )</h3>

1005

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1006

<h3 class="fn"><a name="setNum-6"></a>QString & QString::setNum ( <a href="qtglobal.html#qulonglong-typedef">qulonglong</a> n, int base = 10 )</h3>

1007

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1008

<h3 class="fn"><a name="setNum-7"></a>QString & QString::setNum ( short n, int base = 10 )</h3>

1009

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1010

<h3 class="fn"><a name="setNum-8"></a>QString & QString::setNum ( <a href="qtglobal.html#ushort-typedef">ushort</a> n, int base = 10 )</h3>

1011

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1012

<h3 class="fn"><a name="setNum-9"></a>QString & QString::setNum ( double n, char f = 'g', int prec = 6 )</h3>

1013

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1014

Sets the string to the printed value of n, formatted using format f with precision prec, and returns a reference to the string.

1015

The format f can be 'f', 'F', 'e', 'E', 'g' or 'G'. See arg() for an explanation of the formats.

1016

<h3 class="fn"><a name="setNum-10"></a>QString & QString::setNum ( float n, char f = 'g', int prec = 6 )</h3>

1017

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1018

Sets the string to the printed value of n, formatted in format f with precision prec, and returns a reference to the string.

1019

The format f can be 'f', 'F', 'e', 'E', 'g' or 'G'. See arg() for an explanation of the formats.

1020

<h3 class="fn"><a name="setUnicode"></a>QString & QString::setUnicode ( const <a href="qchar.html">QChar</a> * unicode, int size )</h3>

1021

Resizes the string to size characters and copies unicode into the string.

1022

If unicode is 0, nothing is copied, but the string is still resized to size.

1023

See also <a href="qstring.html#unicode">unicode</a>() and <a href="qstring.html#setUtf16">setUtf16</a>().

1024

<h3 class="fn"><a name="setUtf16"></a>QString & QString::setUtf16 ( const <a href="qtglobal.html#ushort-typedef">ushort</a> * unicode, int size )</h3>

1025

Resizes the string to size characters and copies unicode into the string.

1026

If unicode is 0, nothing is copied, but the string is still resized to size.

1027

See also <a href="qstring.html#utf16">utf16</a>() and <a href="qstring.html#setUnicode">setUnicode</a>().

1028

<h3 class="fn"><a name="simplified"></a>QString QString::simplified () const</h3>

1029

Returns a string that has whitespace removed from the start and the end, and that has each sequence of internal whitespace replaced with a single space.

1030

Whitespace means any character for which <a href="qchar.html#isSpace">QChar::isSpace</a>() returns true. This includes the ASCII characters '\t', '\n', '\v', '\f', '\r', and ' '.

1031

Example:

1032

<pre>  QString str = " lots\t of\nwhitespace\r\n ";

1033

str = str.trimmed();

1034

// str == "lots of whitespace";</pre>

1035

See also <a href="qstring.html#trimmed">trimmed</a>().

1036

<h3 class="fn"><a name="size"></a>int QString::size () const</h3>

1037

Returns the number of characters in this string.

1038

The last character in the string is at position size() - 1. In addition, <a href="qstring.html">QString</a> ensures that the character at position size() is always '\0', so that you can use the return value of <a href="qstring.html#data">data</a>() and <a href="qstring.html#constData">constData</a>() as arguments to functions that expect '\0'-terminated strings.

1039

Example:

1040

<pre>  QString str = "World";

1041

int n = str.size(); // n == 5

1042

str.data()[0]; // returns 'W'

1043

str.data()[4]; // returns 'd'

1044

str.data()[5]; // returns '\0'</pre>

1045

See also <a href="qstring.html#isEmpty">isEmpty</a>() and <a href="qstring.html#resize">resize</a>().

1046

<h3 class="fn"><a name="split"></a><a href="qstringlist.html">QStringList</a> QString::split ( const QString & sep, <a href="qstring.html#SplitBehavior-enum">SplitBehavior</a> behavior = KeepEmptyParts, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

1047

Splits the string into substrings wherever sep occurs, and returns the list of those strings. If sep does not match anywhere in the string, split() returns a single-element list containing this string.

1048

If cs is true, the string is only split only where characters are found that match sep exactly. If cs is false, the string is split, the string is split where characters are found that match sep case insensitively (e.g. "and" matches "AND").

1049

If behavior is <a href="qstring.html#SplitBehavior-enum">QString::SkipEmptyParts</a>, empty entries don't appear in the result. By default, empty entries are kept.

1050

Example:

1051

<pre>  QString str = "a,,b,c";

1052

QStringList list1 = str.split(",");

1053

// list1: [ "a", "", "b", "c" ]

1054

1055

QStringList list2 = str.split(",", QString::SkipEmptyParts);

1056

// list2: [ "a", "b", "c" ]</pre>

1057

See also <a href="qstringlist.html#join">QStringList::join</a>() and <a href="qstring.html#section">section</a>().

1058

<h3 class="fn"><a name="split-2"></a><a href="qstringlist.html">QStringList</a> QString::split ( const <a href="qchar.html">QChar</a> & sep, <a href="qstring.html#SplitBehavior-enum">SplitBehavior</a> behavior = KeepEmptyParts, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

1059

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1060

<h3 class="fn"><a name="split-3"></a><a href="qstringlist.html">QStringList</a> QString::split ( const <a href="qregexp.html">QRegExp</a> & rx, <a href="qstring.html#SplitBehavior-enum">SplitBehavior</a> behavior = KeepEmptyParts ) const</h3>

1061

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1062

Splits the string into substrings wherever the regular expression rx matches, and returns the list of those strings. If rx does not match anywhere in the string, <a href="qstring.html#split">split</a>() returns a single-element list containing this string.

1063

Here's an example where we extract the words in a sentence using one or more whitespace characters as the separator:

1064

<pre>  QString str = "Some text\n\twith strange whitespace.";

1065

QStringList list = str.split(QRegExp("\\s+"));

1066

// list: [ "Some", "text", "with", "strange", "whitespace." ]</pre>

1067

Here's a similar example, but this time we use any sequence of non-word characters as the separator:

1068

<pre>  QString str = "This time, a normal English sentence.";

1069

QStringList list = str.split(QRegExp("\\W+"),

1070

QString::SkipEmptyParts);

1071

// list: [ "This", "time", "a", "normal", "English", "sentence" ]</pre>

1072

Here's a third example where we use a zero-length assertion, \b (word boundary), to split the string into an alternating sequence of non-word and word tokens:

1073

<pre>  QString str = "Now: this sentence fragment.";

1074

QStringList list = str.split(QRegExp("\\b"));

1075

// list: [ "", "Now", ": ", "this", " ", "sentence", " ", "fragment", "." ]</pre>

1076

See also <a href="qstringlist.html#join">QStringList::join</a>() and <a href="qstring.html#section">section</a>().

1077

<h3 class="fn"><a name="sprintf"></a>QString & QString::sprintf ( const char * cformat, ... )</h3>

1078

Safely builds a formatted string from the format string cformat and an arbitrary list of arguments.

1079

The %lc escape sequence expects a unicode character of type ushort (as returned by <a href="qchar.html#unicode">QChar::unicode</a>()). The %ls escape sequence expects a pointer to a zero-terminated array of unicode characters of type ushort (as returned by <a href="qstring.html#utf16">QString::utf16</a>()).

1080

The format string supports most of the conversion specifiers provided by printf() in the standard C++ library. It doesn't honor the length modifiers (e.g. <tt>h</tt> for <tt>short</tt>, <tt>ll</tt> for <tt>long long</tt>). If you need those, use the standard sprintf() function instead:

1081

<pre>  char buf[BufSize];

1082

::sprintf(buf, "%lld", 123456789LL);

1083

QString str = QString::fromAscii(buf);</pre>

1084

Warning: We do not recommend using QString::sprintf() in new Qt code. Instead, consider using <a href="qtextostream.html">QTextOStream</a> or <a href="qstring.html#arg">arg</a>(), both of which support Unicode strings seamlessly and are type-safe. Here's an example that uses <a href="qtextostream.html">QTextOStream</a>:

1085

<pre>  QString result;

1086

QTextOStream(&result) << "pi = " << 3.14;

1087

// result == "pi = 3.14"</pre>

1088

For <a href="qobject.html#tr">translations,</a> especially if the strings contains more than one escape sequence, you should consider using the <a href="qstring.html#arg">arg</a>() function instead. This allows the order of the replacements to be controlled by the translator.

1089

See also <a href="qstring.html#arg">arg</a>().

1090

<h3 class="fn"><a name="squeeze"></a>void QString::squeeze ()</h3>

1091

Releases any memory not required to store the character data.

1092

The sole purpose of this function is to provide a means of fine tuning <a href="qstring.html">QString</a>'s memory usage. In general, you will rarely ever need to call this function.

1093

See also <a href="qstring.html#reserve">reserve</a>() and <a href="qstring.html#capacity">capacity</a>().

1094

<h3 class="fn"><a name="startsWith"></a>bool QString::startsWith ( const QString & s, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

1095

Returns true if the string starts with s; otherwise returns false.

1096

If cs is <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitive</a> (the default), the search is case sensitive; otherwise the search is case insensitive.

1097

<pre>  QString str = "Bananas";

1098

str.startsWith("Ban"); // returns true

1099

str.startsWith("Car"); // returns false</pre>

1100

See also <a href="qstring.html#endsWith">endsWith</a>().

1101

<h3 class="fn"><a name="startsWith-3"></a>bool QString::startsWith ( const <a href="qlatin1string.html">QLatin1String</a> & s, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

1102

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1103

<h3 class="fn"><a name="startsWith-4"></a>bool QString::startsWith ( const <a href="qchar.html">QChar</a> & c, <a href="qt.html#CaseSensitivity-enum">Qt::CaseSensitivity</a> cs = Qt::CaseSensitive ) const</h3>

1104

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1105

<h3 class="fn"><a name="toAscii"></a><a href="qbytearray.html">QByteArray</a> QString::toAscii () const</h3>

1106

Returns an 8-bit ASCII representation of the string as a <a href="qbytearray.html">QByteArray</a>.

1107

If a codec has been set using <a href="qtextcodec.html#setCodecForCStrings">QTextCodec::setCodecForCStrings</a>(), it is used to convert Unicode to 8-bit char; otherwise this function does the same as <a href="qstring.html#toLatin1">toLatin1</a>().

1108

See also <a href="qstring.html#fromAscii">fromAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>(), and <a href="qtextcodec.html">QTextCodec</a>.

1109

<h3 class="fn"><a name="toDouble"></a>double QString::toDouble ( bool * ok = 0 ) const</h3>

1110

Returns the string converted to a <tt>double</tt> value.

1111

Returns 0.0 if the conversion fails.

1112

If ok is not 0: if a conversion error occurs, <tt>*</tt>ok is set to false; otherwise <tt>*</tt>ok is set to true.

1113

<pre>  QString str = "1234.56";

1114

double val = str.toDouble(); // val == 1234.56</pre>

1115

This function tries to interpret the string according to the current locale. The current locale is determined from the system at application startup and can be changed by calling <a href="qlocale.html#setDefault">QLocale::setDefault</a>(). If the string cannot be interpreted according to the current locale, this function falls back on the "C" locale.

1116

<pre>  bool ok;

1117

double d;

1118

1119

QLocale::setDefault(QLocale::C);

1120

d = QString( "1234,56" ).toDouble(&ok); // ok == false

1121

d = QString( "1234.56" ).toDouble(&ok); // ok == true, d == 1234.56

1122

1123

QLocale::setDefault(QLocale::German);

1124

d = QString( "1234,56" ).toDouble(&ok); // ok == true, d == 1234.56

1125

d = QString( "1234.56" ).toDouble(&ok); // ok == true, d == 1234.56</pre>

1126

Due to the ambiguity between the decimal point and thousands group separator in various locales, this function does not handle thousands group separators. If you need to convert such numbers, see <a href="qlocale.html#toDouble">QLocale::toDouble</a>().

1127

<pre>  bool ok;

1128

QLocale::setDefault(QLocale::C);

1129

double d = QString( "1,234,567.89" ).toDouble(&ok); // ok == false</pre>

1130

Warning: If the string contains trailing whitespace this function will fail, and set <tt>*</tt>ok to false if ok is not 0. Leading whitespace is ignored.

1131

See also <a href="qstring.html#number">number</a>(), <a href="qlocale.html#setDefault">QLocale::setDefault</a>(), <a href="qlocale.html#toDouble">QLocale::toDouble</a>(), and <a href="qstring.html#trimmed">trimmed</a>().

1132

<h3 class="fn"><a name="toFloat"></a>float QString::toFloat ( bool * ok = 0 ) const</h3>

1133

Returns the string converted to a <tt>float</tt> value.

1134

Returns 0.0 if the conversion fails.

1135

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1136

Example:

1137

<pre>  QString str1 = "1234.56";

1138

str1.toFloat(); // returns 1234.56

1139

1140

bool ok;

1141

QString str2 = "R2D2";

1142

str2.toFloat(&ok); // returns 0.0, sets ok to false</pre>

1143

See also <a href="qstring.html#number">number</a>(), <a href="qstring.html#toDouble">toDouble</a>(), and <a href="qstring.html#toInt">toInt</a>().

1144

<h3 class="fn"><a name="toInt"></a>int QString::toInt ( bool * ok = 0, int base = 10 ) const</h3>

1145

Returns the string converted to an <tt>int</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1146

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1147

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1148

Example:

1149

<pre>  QString str = "FF";

1150

bool ok;

1151

int hex = str.toInt(&ok, 16); // hex == 255, ok == true

1152

int dec = str.toInt(&ok, 10); // dec == 0, ok == false</pre>

1153

See also <a href="qstring.html#number">number</a>(), <a href="qstring.html#toUInt">toUInt</a>(), and <a href="qstring.html#toDouble">toDouble</a>().

1154

<h3 class="fn"><a name="toLatin1"></a><a href="qbytearray.html">QByteArray</a> QString::toLatin1 () const</h3>

1155

Returns a Latin-1 representation of the string as a <a href="qbytearray.html">QByteArray</a>. The returned byte array is undefined if the string contains non-Latin1 characters.

1156

See also <a href="qstring.html#fromLatin1">fromLatin1</a>(), <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>(), and <a href="qtextcodec.html">QTextCodec</a>.

1157

<h3 class="fn"><a name="toLocal8Bit"></a><a href="qbytearray.html">QByteArray</a> QString::toLocal8Bit () const</h3>

1158

Returns the local 8-bit representation of the string as a <a href="qbytearray.html">QByteArray</a>. The returned byte array is undefined if the string contains characters not supported by the local 8-bit encoding.

1159

<a href="qtextcodec.html#codecForLocale">QTextCodec::codecForLocale</a>() is used to perform the conversion from Unicode.

1160

See also <a href="qstring.html#fromLocal8Bit">fromLocal8Bit</a>(), <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), and <a href="qtextcodec.html">QTextCodec</a>.

1161

<h3 class="fn"><a name="toLong"></a>long QString::toLong ( bool * ok = 0, int base = 10 ) const</h3>

1162

Returns the string converted to a <tt>long</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1163

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1164

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1165

Example:

1166

<pre>  QString str = "FF";

1167

bool ok;

1168

long hex = str.toLong(&ok, 16); // hex == 255, ok == true

1169

long dec = str.toLong(&ok, 10); // dec == 0, ok == false</pre>

1170

See also <a href="qstring.html#number">number</a>(), <a href="qstring.html#toULong">toULong</a>(), and <a href="qstring.html#toInt">toInt</a>().

1171

<h3 class="fn"><a name="toLongLong"></a><a href="qtglobal.html#qlonglong-typedef">qlonglong</a> QString::toLongLong ( bool * ok = 0, int base = 10 ) const</h3>

1172

Returns the string converted to a <tt>long long</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1173

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1174

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1175

Example:

1176

<pre>  QString str = "FF";

1177

bool ok;

1178

qint64 hex = str.toLongLong(&ok, 16); // hex == 255, ok == true

1179

qint64 dec = str.toLongLong(&ok, 10); // dec == 0, ok == false</pre>

1180

See also <a href="qstring.html#number">number</a>(), <a href="qstring.html#toULongLong">toULongLong</a>(), and <a href="qstring.html#toInt">toInt</a>().

1181

<h3 class="fn"><a name="toLower"></a>QString QString::toLower () const</h3>

1182

Returns a lowercase copy of the string.

1183

<pre>  QString str = "TROlltECH";

1184

str = str.toLower(); // str == "trolltech"</pre>

1185

See also <a href="qstring.html#toUpper">toUpper</a>().

1186

<h3 class="fn"><a name="toShort"></a>short QString::toShort ( bool * ok = 0, int base = 10 ) const</h3>

1187

Returns the string converted to a <tt>short</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1188

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1189

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1190

Example:

1191

<pre>  QString str = "FF";

1192

bool ok;

1193

short hex = str.toShort(&ok, 16); // hex == 255, ok == true

1194

short dec = str.toShort(&ok, 10); // dec == 0, ok == false</pre>

1195

See also <a href="qstring.html#number">number</a>(), <a href="qstring.html#toUShort">toUShort</a>(), and <a href="qstring.html#toInt">toInt</a>().

1196

<h3 class="fn"><a name="toStdString"></a>std::string QString::toStdString () const</h3>

1197

Returns a std::string object with the data contained in this <a href="qstring.html">QString</a>. The Unicode data is converted into 8-bit characters using <a href="qstring.html#toAscii">toAscii</a>().

1198

This operator is mostly useful to pass a <a href="qstring.html">QString</a> to a function that accepts a std::string object.

1199

If the <a href="qstring.html">QString</a> contains non-ASCII Unicode characters, using this operator can lead to loss of information. You can disable this operator by defining <tt>QT_NO_CAST_TO_ASCII</tt> when you compile your applications. You then need to call <a href="qstring.html#toAscii">toAscii</a>() (or <a href="qstring.html#toLatin1">toLatin1</a>() or <a href="qstring.html#toUtf8">toUtf8</a>() or <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>()) explicitly if you want to convert the data to <tt>const char *</tt> and pass the return value on to the std::string constructor.

1200

This operator is only available if Qt is configured with STL compabitility enabled.

1201

See also <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), and <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>().

1202

<h3 class="fn"><a name="toStdWString"></a>std::wstring QString::toStdWString () const</h3>

1203

Returns a std::wstring object with the data contained in this <a href="qstring.html">QString</a>. The std::wstring is encoded in utf16 on platforms where wchar_t is 2 bytes wide (e.g. windows) and in ucs4 on platforms where wchar_t is 4 bytes wide (most Unix systems).

1204

This operator is mostly useful to pass a <a href="qstring.html">QString</a> to a function that accepts a std::wstring object.

1205

This operator is only available if Qt is configured with STL compabitility enabled.

1206

See also <a href="qstring.html#utf16">utf16</a>(), <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toUtf8">toUtf8</a>(), and <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>().

1207

<h3 class="fn"><a name="toUInt"></a><a href="qtglobal.html#uint-typedef">uint</a> QString::toUInt ( bool * ok = 0, int base = 10 ) const</h3>

1208

Returns the string converted to an <tt>unsigned int</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1209

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1210

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1211

Example:

1212

<pre>  QString str = "FF";

1213

bool ok;

1214

uint hex = str.toUInt(&ok, 16); // hex == 255, ok == true

1215

uint dec = str.toUInt(&ok, 10); // dec == 0, ok == false</pre>

1216

See also <a href="qstring.html#number">number</a>() and <a href="qstring.html#toInt">toInt</a>().

1217

<h3 class="fn"><a name="toULong"></a><a href="qtglobal.html#ulong-typedef">ulong</a> QString::toULong ( bool * ok = 0, int base = 10 ) const</h3>

1218

Returns the string converted to an <tt>unsigned long</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1219

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1220

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1221

Example:

1222

<pre>  QString str = "FF";

1223

bool ok;

1224

ulong hex = str.toULong(&ok, 16); // hex == 255, ok == true

1225

ulong dec = str.toULong(&ok, 10); // dec == 0, ok == false</pre>

1226

See also <a href="qstring.html#number">number</a>().

1227

<h3 class="fn"><a name="toULongLong"></a><a href="qtglobal.html#qulonglong-typedef">qulonglong</a> QString::toULongLong ( bool * ok = 0, int base = 10 ) const</h3>

1228

Returns the string converted to an <tt>unsigned long long</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1229

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1230

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1231

Example:

1232

<pre>  QString str = "FF";

1233

bool ok;

1234

quint64 hex = str.toULongLong(&ok, 16); // hex == 255, ok == true

1235

quint64 dec = str.toULongLong(&ok, 10); // dec == 0, ok == false</pre>

1236

See also <a href="qstring.html#number">number</a>() and <a href="qstring.html#toLongLong">toLongLong</a>().

1237

<h3 class="fn"><a name="toUShort"></a><a href="qtglobal.html#ushort-typedef">ushort</a> QString::toUShort ( bool * ok = 0, int base = 10 ) const</h3>

1238

Returns the string converted to an <tt>unsigned short</tt> using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

1239

If ok is not 0: if a conversion error occurs, *ok is set to false; otherwise *ok is set to true.

1240

If base is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

1241

Example:

1242

<pre>  QString str = "FF";

1243

bool ok;

1244

ushort hex = str.toUShort(&ok, 16); // hex == 255, ok == true

1245

ushort dec = str.toUShort(&ok, 10); // dec == 0, ok == false</pre>

1246

See also <a href="qstring.html#number">number</a>() and <a href="qstring.html#toShort">toShort</a>().

1247

<h3 class="fn"><a name="toUpper"></a>QString QString::toUpper () const</h3>

1248

Returns an uppercase copy of the string.

1249

<pre>  QString str = "TeXt";

1250

str = str.toUpper(); // str == "TEXT"</pre>

1251

See also <a href="qstring.html#toLower">toLower</a>().

1252

<h3 class="fn"><a name="toUtf8"></a><a href="qbytearray.html">QByteArray</a> QString::toUtf8 () const</h3>

1253

Returns a UTF-8 representation of the string as a <a href="qbytearray.html">QByteArray</a>.

1254

See also <a href="qstring.html#fromUtf8">fromUtf8</a>(), <a href="qstring.html#toAscii">toAscii</a>(), <a href="qstring.html#toLatin1">toLatin1</a>(), <a href="qstring.html#toLocal8Bit">toLocal8Bit</a>(), and <a href="qtextcodec.html">QTextCodec</a>.

1255

<h3 class="fn"><a name="trimmed"></a>QString QString::trimmed () const</h3>

1256

Returns a string that has whitespace removed from the start and the end.

1257

Whitespace means any character for which <a href="qchar.html#isSpace">QChar::isSpace</a>() returns true. This includes the ASCII characters '\t', '\n', '\v', '\f', '\r', and ' '.

1258

Example:

1259

<pre>  QString str = " lots\t of\nwhitespace\r\n ";

1260

str = str.trimmed();

1261

// str == "lots\t of\nwhitespace";</pre>

1262

Unlike <a href="qstring.html#simplified">simplified</a>(), trimmed() leaves internal whitespace alone.

1263

See also <a href="qstring.html#simplified">simplified</a>().

1264

<h3 class="fn"><a name="truncate"></a>void QString::truncate ( int pos )</h3>

1265

Truncates the string at index position pos.

1266

If pos is beyond the end of the string, nothing happens.

1267

Example:

1268

<pre>  QString str = "Vladivostok";

1269

str.truncate(4);

1270

// str == "Vlad"</pre>

1271

See also <a href="qstring.html#chop">chop</a>(), <a href="qstring.html#resize">resize</a>(), and <a href="qstring.html#left">left</a>().

1272

<h3 class="fn"><a name="unicode"></a>const <a href="qchar.html">QChar</a> * QString::unicode () const</h3>

1273

Returns a '\0'-terminated Unicode representation of the string. The result remains valid until the string is modified.

1274

See also <a href="qstring.html#utf16">utf16</a>().

1275

<h3 class="fn"><a name="utf16"></a>const <a href="qtglobal.html#ushort-typedef">ushort</a> * QString::utf16 () const</h3>

1276

Returns the <a href="qstring.html">QString</a> as a '\0'-terminated array of unsigned shorts. The result remains valid until the string is modified.

1277

See also <a href="qstring.html#unicode">unicode</a>().

1278

<h3 class="fn"><a name="vsprintf"></a>QString & QString::vsprintf ( const char * cformat, va_list ap )</h3>

1279

Equivalent method to <a href="qstring.html#sprintf">sprintf</a>(), but takes a va_list ap instead a list of variable arguments. See the <a href="qstring.html#sprintf">sprintf</a>() documentation for an explanation of cformat.

1280

This method does not call the va_end macro, the caller is responsible to call va_end on ap.

1281

See also <a href="qstring.html#sprintf">sprintf</a>().

1282

<h3 class="fn"><a name="operator-not-eq"></a>bool QString::operator!= ( const QString & other ) const</h3>

1283

Returns true if this string is not equal to string other; otherwise returns false.

1284

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with <a href="qstring.html#localeAwareCompare">localeAwareCompare</a>().

1285

<h3 class="fn"><a name="operator-not-eq-2"></a>bool QString::operator!= ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1286

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1287

<h3 class="fn"><a name="operator-not-eq-3"></a>bool QString::operator!= ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1288

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1289

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1290

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through <a href="qobject.html#tr">QObject::tr</a>(), for example.

1291

<h3 class="fn"><a name="operator-not-eq-4"></a>bool QString::operator!= ( const char * other ) const</h3>

1292

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1293

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1294

1295

<h3 class="fn"><a name="operator-2b-eq"></a>QString & QString::operator+= ( const QString & other )</h3>

1296

Appends the string other onto the end of this string and returns a reference to this string.

1297

Example:

1298

<pre>  QString x = "free";

1299

QString y = "dom";

1300

x += y;

1301

// x == "freedom"</pre>

1302

1303

See also <a href="qstring.html#append">append</a>() and <a href="qstring.html#prepend">prepend</a>().

1304

<h3 class="fn"><a name="operator-2b-eq-2"></a>QString & QString::operator+= ( const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

1305

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1306

Appends the Latin-1 string str to this string.

1307

<h3 class="fn"><a name="operator-2b-eq-3"></a>QString & QString::operator+= ( const <a href="qbytearray.html">QByteArray</a> & ba )</h3>

1308

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1309

Appends the byte array ba to this string. ba is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1310

1311

<h3 class="fn"><a name="operator-2b-eq-4"></a>QString & QString::operator+= ( const char * str )</h3>

1312

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1313

Appends the string str to this string. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1314

1315

<h3 class="fn"><a name="operator-2b-eq-5"></a>QString & QString::operator+= ( char ch )</h3>

1316

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1317

Appends the character ch to this string. The character is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1318

1319

<h3 class="fn"><a name="operator-2b-eq-6"></a>QString & QString::operator+= ( <a href="qchar.html">QChar</a> ch )</h3>

1320

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1321

Appends the character ch to the string.

1322

<h3 class="fn"><a name="operator-lt"></a>bool QString::operator< ( const QString & other ) const</h3>

1323

Returns true if this string is lexically less than string other; otherwise returns false.

1324

1325

<h3 class="fn"><a name="operator-lt-2"></a>bool QString::operator< ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1326

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1327

<h3 class="fn"><a name="operator-lt-3"></a>bool QString::operator< ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1328

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1329

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1330

1331

<h3 class="fn"><a name="operator-lt-4"></a>bool QString::operator< ( const char * other ) const</h3>

1332

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1333

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1334

1335

<h3 class="fn"><a name="operator-lt-eq"></a>bool QString::operator<= ( const QString & other ) const</h3>

1336

Returns true if this string is lexically less than or equal to string other; otherwise returns false.

1337

1338

<h3 class="fn"><a name="operator-lt-eq-2"></a>bool QString::operator<= ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1339

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1340

<h3 class="fn"><a name="operator-lt-eq-3"></a>bool QString::operator<= ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1341

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1342

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1343

1344

<h3 class="fn"><a name="operator-lt-eq-4"></a>bool QString::operator<= ( const char * other ) const</h3>

1345

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1346

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1347

1348

<h3 class="fn"><a name="operator-eq"></a>QString & QString::operator= ( const QString & other )</h3>

1349

Assigns other to this string and returns a reference to this string.

1350

<h3 class="fn"><a name="operator-eq-3"></a>QString & QString::operator= ( const <a href="qlatin1string.html">QLatin1String</a> & str )</h3>

1351

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1352

Assigns the Latin-1 string str to this string.

1353

<h3 class="fn"><a name="operator-eq-4"></a>QString & QString::operator= ( const <a href="qbytearray.html">QByteArray</a> & ba )</h3>

1354

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1355

Assigns ba to this string. ba is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1356

1357

<h3 class="fn"><a name="operator-eq-5"></a>QString & QString::operator= ( const char * str )</h3>

1358

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1359

Assigns str to this string. str is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1360

1361

<h3 class="fn"><a name="operator-eq-6"></a>QString & QString::operator= ( char ch )</h3>

1362

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1363

Assigns character ch to this string. The character is converted to Unicode using <a href="qstring.html#fromAscii">fromAscii</a>().

1364

1365

<h3 class="fn"><a name="operator-eq-7"></a>QString & QString::operator= ( <a href="qchar.html">QChar</a> ch )</h3>

1366

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1367

Sets the string to contain the single character ch.

1368

<h3 class="fn"><a name="operator-eq-eq"></a>bool QString::operator== ( const QString & other ) const</h3>

1369

Returns true if string other is equal to this string; otherwise returns false.

1370

1371

<h3 class="fn"><a name="operator-eq-eq-2"></a>bool QString::operator== ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1372

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1373

<h3 class="fn"><a name="operator-eq-eq-3"></a>bool QString::operator== ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1374

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1375

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1376

1377

<h3 class="fn"><a name="operator-eq-eq-4"></a>bool QString::operator== ( const char * other ) const</h3>

1378

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1379

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1380

1381

<h3 class="fn"><a name="operator-gt"></a>bool QString::operator> ( const QString & other ) const</h3>

1382

Returns true if this string is lexically greater than string other; otherwise returns false.

1383

1384

<h3 class="fn"><a name="operator-gt-2"></a>bool QString::operator> ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1385

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1386

<h3 class="fn"><a name="operator-gt-3"></a>bool QString::operator> ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1387

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1388

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1389

1390

<h3 class="fn"><a name="operator-gt-4"></a>bool QString::operator> ( const char * other ) const</h3>

1391

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1392

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1393

1394

<h3 class="fn"><a name="operator-gt-eq"></a>bool QString::operator>= ( const QString & other ) const</h3>

1395

Returns true if this string is lexically greater than or equal to string other; otherwise returns false.

1396

1397

<h3 class="fn"><a name="operator-gt-eq-2"></a>bool QString::operator>= ( const <a href="qlatin1string.html">QLatin1String</a> & other ) const</h3>

1398

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1399

<h3 class="fn"><a name="operator-gt-eq-3"></a>bool QString::operator>= ( const <a href="qbytearray.html">QByteArray</a> & other ) const</h3>

1400

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1401

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1402

1403

<h3 class="fn"><a name="operator-gt-eq-4"></a>bool QString::operator>= ( const char * other ) const</h3>

1404

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1405

other is converted to a <a href="qstring.html">QString</a> using <a href="qstring.html#fromAscii">fromAscii</a>().

1406

1407

<h3 class="fn"><a name="operator-5b-5d"></a><a href="qcharref.html">QCharRef</a> QString::operator[] ( int i )</h3>

1408

Returns the character at index position i as a modifiable reference.

1409

Example:

1410

<pre>  if (str[0] == QChar('?'))

1411

str[0] = QChar('_');</pre>

1412

The return value is of type <a href="qcharref.html">QCharRef</a>, a helper class for <a href="qstring.html">QString</a>. When you get an object of type <a href="qcharref.html">QCharRef</a>, you can use it as if it were a <a href="qchar.html">QChar</a> &. If you assign to it, the assignment will apply to the character in the <a href="qstring.html">QString</a> from which you got the reference.

1413

See also <a href="qstring.html#at">at</a>().

1414

<h3 class="fn"><a name="operator-5b-5d-2"></a>const <a href="qchar.html">QChar</a> QString::operator[] ( int i ) const</h3>

1415

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1416

Same as at(i).

1417

<h3 class="fn"><a name="operator-5b-5d-3"></a><a href="qcharref.html">QCharRef</a> QString::operator[] ( <a href="qtglobal.html#uint-typedef">uint</a> i )</h3>

1418

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1419

<h3 class="fn"><a name="operator-5b-5d-4"></a>const <a href="qchar.html">QChar</a> QString::operator[] ( <a href="qtglobal.html#uint-typedef">uint</a> i ) const</h3>

1420

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1421

<hr />

1422

<h2>Related Non-Members</h2>

1423

<h3 class="fn"><a name="operator-not-eq-30"></a>bool operator!= ( const char * s1, const QString & s2 )</h3>

1424

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1425

Returns true if s1 is not equal to s2; otherwise returns false. Note that no string is equal to s1 being 0.

1426

For s1 != 0, this is equivalent to compare(s1, s2) != 0.

1427

<h3 class="fn"><a name="operator-2b-7"></a>const QString operator+ ( const QString & s1, const QString & s2 )</h3>

1428

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1429

Returns a string which is the result of concatenating the string s1 and the string s2.

1430

<h3 class="fn"><a name="operator-2b-20"></a>const QString operator+ ( const QString & s1, const char * s2 )</h3>

1431

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1432

Returns a string which is the result of concatenating the string s1 and the string s2. s2 is converted to Unicode using fromAscii().

1433

<h3 class="fn"><a name="operator-2b-21"></a>const QString operator+ ( const char * s1, const QString & s2 )</h3>

1434

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1435

Returns a string which is the result of concatenating the string s1 and string s2. s1 is converted to Unicode using fromAscii().

1436

<h3 class="fn"><a name="operator-2b-22"></a>const QString operator+ ( const QString & s, char ch )</h3>

1437

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1438

Returns a string which is the result of concatenating the string s and character ch.

1439

<h3 class="fn"><a name="operator-2b-23"></a>const QString operator+ ( char ch, const QString & s )</h3>

1440

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1441

Returns a string which is the result of concatenating the character ch and string s.

1442

<h3 class="fn"><a name="operator-lt-11"></a>bool operator< ( const char * s1, const QString & s2 )</h3>

1443

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1444

Returns true if s1 is lexically less than s2; otherwise returns false.

1445

1446

For s1 != 0, equivalent to compare(s1, s2) < 0.

1447

<h3 class="fn"><a name="operator-lt-lt-52"></a><a href="qdatastream.html">QDataStream</a> & operator<< ( <a href="qdatastream.html">QDataStream</a> & out, const QString & str )</h3>

1448

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1449

Writes the string str to the stream out.

1450

See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.

1451

<h3 class="fn"><a name="operator-lt-eq-11"></a>bool operator<= ( const char * s1, const QString & s2 )</h3>

1452

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1453

Returns true if s1 is lexically less than or equal to s2; otherwise returns false.

1454

1455

For s1 != 0, this is equivalent to compare(s1, s2) <= 0.

1456

<h3 class="fn"><a name="operator-eq-eq-40"></a>bool operator== ( const char * s1, const QString & s2 )</h3>

1457

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1458

Returns true if s1 is equal to s2; otherwise returns false. Note that no string is equal to s1 being 0.

1459

Equivalent to s1 != 0 && compare(s1, s2) == 0.

1460

<h3 class="fn"><a name="operator-gt-11"></a>bool operator> ( const char * s1, const QString & s2 )</h3>

1461

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1462

Returns true if s1 is lexically greater than s2; otherwise returns false.

1463

1464

Equivalent to compare(s1, s2) > 0.

1465

<h3 class="fn"><a name="operator-gt-eq-11"></a>bool operator>= ( const char * s1, const QString & s2 )</h3>

1466

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1467

Returns true if s1 is lexically greater than or equal to s2; otherwise returns false.

1468

1469

For s1 != 0, this is equivalent to compare(s1, s2) >= 0.

1470

<h3 class="fn"><a name="operator-gt-gt-33"></a><a href="qdatastream.html">QDataStream</a> & operator>> ( <a href="qdatastream.html">QDataStream</a> & in, QString & str )</h3>

1471

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

1472

Reads a string from the stream in into string str.

1473

See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.

1474

1475

1476

1477

<td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td>

1478

1479

</tr></table></div></address></body>

1480

</html>

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