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<?xml version="1.0" encoding="UTF-8"?>
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<title>Qt 4.8: QLatin1String Class Reference</title>
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<a href="index.html" class="qtref"><span>Qt Reference Documentation</span></a>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#public-functions">Public Functions</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
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<h1 class="title">QLatin1String Class Reference</h1>
<!-- $$$QLatin1String-brief -->
<p>The QLatin1String class provides a thin wrapper around an US-ASCII/Latin-1 encoded string literal. <a href="#details">More...</a></p>
<!-- @@@QLatin1String -->
<pre class="cpp"> <span class="preprocessor">#include <QLatin1String></span></pre><p><b>Note:</b> All functions in this class are <a href="threads-reentrancy.html#reentrant">reentrant</a>.</p>
<ul>
<li><a href="qlatin1string-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h2>Public Functions</h2>
<table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#QLatin1String">QLatin1String</a></b> ( const char * <i>str</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> const char * </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#latin1">latin1</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-not-eq">operator!=</a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-not-eq-2">operator!=</a></b> ( const char * <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-lt">operator<</a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-lt-2">operator<</a></b> ( const char * <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-lt-eq">operator<=</a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-lt-eq-2">operator<=</a></b> ( const char * <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QLatin1String & </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-eq">operator=</a></b> ( const QLatin1String & <i>other</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-eq-eq">operator==</a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-eq-eq-2">operator==</a></b> ( const char * <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-gt">operator></a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-gt-2">operator></a></b> ( const char * <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-gt-eq">operator>=</a></b> ( const QString & <i>other</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlatin1string.html#operator-gt-eq-2">operator>=</a></b> ( const char * <i>other</i> ) const</td></tr>
</table>
<a name="details"></a>
<!-- $$$QLatin1String-description -->
<div class="descr">
<h2>Detailed Description</h2>
<p>The QLatin1String class provides a thin wrapper around an US-ASCII/Latin-1 encoded string literal.</p>
<p>Many of <a href="qstring.html">QString</a>'s member functions are overloaded to accept <tt>const char *</tt> instead of <a href="qstring.html">QString</a>. This includes the copy constructor, the assignment operator, the comparison operators, and various other functions such as <a href="qstring.html#insert">insert()</a>, <a href="qstring.html#replace">replace()</a>, and <a href="qstring.html#indexOf">indexOf()</a>. These functions are usually optimized to avoid constructing a <a href="qstring.html">QString</a> object for the <tt>const char *</tt> data. For example, assuming <tt>str</tt> is a <a href="qstring.html">QString</a>,</p>
<pre class="cpp"> <span class="keyword">if</span> (str <span class="operator">=</span><span class="operator">=</span> <span class="string">"auto"</span> <span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="string">"extern"</span>
<span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="string">"static"</span> <span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="string">"register"</span>) {
<span class="operator">.</span><span class="operator">.</span><span class="operator">.</span>
}</pre>
<p>is much faster than</p>
<pre class="cpp"> <span class="keyword">if</span> (str <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qstring.html">QString</a></span>(<span class="string">"auto"</span>) <span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qstring.html">QString</a></span>(<span class="string">"extern"</span>)
<span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qstring.html">QString</a></span>(<span class="string">"static"</span>) <span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qstring.html">QString</a></span>(<span class="string">"register"</span>)) {
<span class="operator">.</span><span class="operator">.</span><span class="operator">.</span>
}</pre>
<p>because it doesn't construct four temporary <a href="qstring.html">QString</a> objects and make a deep copy of the character data.</p>
<p>Applications that define <tt>QT_NO_CAST_FROM_ASCII</tt> (as explained in the <a href="qstring.html">QString</a> documentation) don't have access to <a href="qstring.html">QString</a>'s <tt>const char *</tt> API. To provide an efficient way of specifying constant Latin-1 strings, Qt provides the QLatin1String, which is just a very thin wrapper around a <tt>const char *</tt>. Using QLatin1String, the example code above becomes</p>
<pre class="cpp"> <span class="keyword">if</span> (str <span class="operator">=</span><span class="operator">=</span> QLatin1String(<span class="string">"auto"</span>)
<span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> QLatin1String(<span class="string">"extern"</span>)
<span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> QLatin1String(<span class="string">"static"</span>)
<span class="operator">|</span><span class="operator">|</span> str <span class="operator">=</span><span class="operator">=</span> QLatin1String(<span class="string">"register"</span>) {
<span class="operator">.</span><span class="operator">.</span><span class="operator">.</span>
}</pre>
<p>This is a bit longer to type, but it provides exactly the same benefits as the first version of the code, and is faster than converting the Latin-1 strings using <a href="qstring.html#fromLatin1">QString::fromLatin1</a>().</p>
<p>Thanks to the <a href="qstring.html">QString</a>(const QLatin1String &) constructor, QLatin1String can be used everywhere a <a href="qstring.html">QString</a> is expected. For example:</p>
<pre class="cpp"> <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>label <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(QLatin1String(<span class="string">"MOD"</span>)<span class="operator">,</span> <span class="keyword">this</span>);</pre>
</div>
<p><b>See also </b><a href="qstring.html">QString</a> and <a href="qlatin1char.html">QLatin1Char</a>.</p>
<!-- @@@QLatin1String -->
<div class="func">
<h2>Member Function Documentation</h2>
<!-- $$$QLatin1String[overload1]$$$QLatin1Stringconstchar* -->
<h3 class="fn"><a name="QLatin1String"></a>QLatin1String::<span class="name">QLatin1String</span> ( const <span class="type">char</span> * <i>str</i> )</h3>
<p>Constructs a <a href="qlatin1string.html">QLatin1String</a> object that stores <i>str</i>. Note that if <i>str</i> is 0, an empty string is created; this case is handled by <a href="qstring.html">QString</a>.</p>
<p>The string data is <i>not</i> copied. The caller must be able to guarantee that <i>str</i> will not be deleted or modified as long as the <a href="qlatin1string.html">QLatin1String</a> object exists.</p>
<p><b>See also </b><a href="qlatin1string.html#latin1">latin1</a>().</p>
<!-- @@@QLatin1String -->
<!-- $$$latin1[overload1]$$$latin1 -->
<h3 class="fn"><a name="latin1"></a>const <span class="type">char</span> * QLatin1String::<span class="name">latin1</span> () const</h3>
<p>Returns the Latin-1 string stored in this object.</p>
<!-- @@@latin1 -->
<!-- $$$operator!=[overload1]$$$operator!=constQString& -->
<h3 class="fn"><a name="operator-not-eq"></a><span class="type">bool</span> QLatin1String::<span class="name">operator!=</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is not equal to string <i>other</i>; otherwise returns false.</p>
<p>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">QString::localeAwareCompare</a>().</p>
<!-- @@@operator!= -->
<!-- $$$operator!=$$$operator!=constchar* -->
<h3 class="fn"><a name="operator-not-eq-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator!=</span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This function overloads <a href="qlatin1string.html#operator-not-eq">operator!=</a>().</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator!= -->
<!-- $$$operator<[overload1]$$$operator<constQString& -->
<h3 class="fn"><a name="operator-lt"></a><span class="type">bool</span> QLatin1String::<span class="name">operator<</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is lexically less than the <i>other</i> string; otherwise returns false.</p>
<p>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 using the <a href="qstring.html#localeAwareCompare">QString::localeAwareCompare</a>() function.</p>
<!-- @@@operator< -->
<!-- $$$operator<$$$operator<constchar* -->
<h3 class="fn"><a name="operator-lt-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator<</span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This is an overloaded function.</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator< -->
<!-- $$$operator<=[overload1]$$$operator<=constQString& -->
<h3 class="fn"><a name="operator-lt-eq"></a><span class="type">bool</span> QLatin1String::<span class="name">operator<=</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is lexically less than or equal to string <i>other</i>; otherwise returns false.</p>
<p>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">QString::localeAwareCompare</a>().</p>
<!-- @@@operator<= -->
<!-- $$$operator<=$$$operator<=constchar* -->
<h3 class="fn"><a name="operator-lt-eq-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator<=</span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This is an overloaded function.</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator<= -->
<!-- $$$operator=[overload1]$$$operator=constQLatin1String& -->
<h3 class="fn"><a name="operator-eq"></a><span class="type">QLatin1String</span> & QLatin1String::<span class="name">operator=</span> ( const <span class="type">QLatin1String</span> & <i>other</i> )</h3>
<p>Constructs a copy of <i>other</i>.</p>
<p>This function was introduced in Qt 4.1.</p>
<!-- @@@operator= -->
<!-- $$$operator==[overload1]$$$operator==constQString& -->
<h3 class="fn"><a name="operator-eq-eq"></a><span class="type">bool</span> QLatin1String::<span class="name">operator==</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is equal to string <i>other</i>; otherwise returns false.</p>
<p>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">QString::localeAwareCompare</a>().</p>
<!-- @@@operator== -->
<!-- $$$operator==$$$operator==constchar* -->
<h3 class="fn"><a name="operator-eq-eq-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator==</span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This is an overloaded function.</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator== -->
<!-- $$$operator>[overload1]$$$operator>constQString& -->
<h3 class="fn"><a name="operator-gt"></a><span class="type">bool</span> QLatin1String::<span class="name">operator></span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is lexically greater than string <i>other</i>; otherwise returns false.</p>
<p>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">QString::localeAwareCompare</a>().</p>
<!-- @@@operator> -->
<!-- $$$operator>$$$operator>constchar* -->
<h3 class="fn"><a name="operator-gt-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator></span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This is an overloaded function.</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator> -->
<!-- $$$operator>=[overload1]$$$operator>=constQString& -->
<h3 class="fn"><a name="operator-gt-eq"></a><span class="type">bool</span> QLatin1String::<span class="name">operator>=</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>other</i> ) const</h3>
<p>Returns true if this string is lexically greater than or equal to string <i>other</i>; otherwise returns false.</p>
<p>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">QString::localeAwareCompare</a>().</p>
<!-- @@@operator>= -->
<!-- $$$operator>=$$$operator>=constchar* -->
<h3 class="fn"><a name="operator-gt-eq-2"></a><span class="type">bool</span> QLatin1String::<span class="name">operator>=</span> ( const <span class="type">char</span> * <i>other</i> ) const</h3>
<p>This is an overloaded function.</p>
<p>The <i>other</i> const char pointer is converted to a <a href="qstring.html">QString</a> using the <a href="qstring.html#fromAscii">QString::fromAscii</a>() function.</p>
<p>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.</p>
<p>This function was introduced in Qt 4.3.</p>
<!-- @@@operator>= -->
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