<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/reggie/tmp/qt-3.1-reggie-23625/qt-x11-free-3.1.1/src/tools/qstringlist.cpp:46 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>QStringList Class</title> <style type="text/css"><!-- h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QStringList Class Reference</h1> <p>The QStringList class provides a list of strings. <a href="#details">More...</a> <p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when Qt is built with thread support.</p> <p><tt>#include <<a href="qstringlist-h.html">qstringlist.h</a>></tt> <p>Inherits <a href="qvaluelist.html">QValueList</a><QString>. <p><a href="qstringlist-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li><div class=fn><a href="#QStringList"><b>QStringList</b></a> ()</div></li> <li><div class=fn><a href="#QStringList-2"><b>QStringList</b></a> ( const QStringList & l )</div></li> <li><div class=fn><a href="#QStringList-3"><b>QStringList</b></a> ( const QValueList<QString> & l )</div></li> <li><div class=fn><a href="#QStringList-4"><b>QStringList</b></a> ( const QString & i )</div></li> <li><div class=fn><a href="#QStringList-5"><b>QStringList</b></a> ( const char * i )</div></li> <li><div class=fn>void <a href="#sort"><b>sort</b></a> ()</div></li> <li><div class=fn>QString <a href="#join"><b>join</b></a> ( const QString & sep ) const</div></li> <li><div class=fn>QStringList <a href="#grep"><b>grep</b></a> ( const QString & str, bool cs = TRUE ) const</div></li> <li><div class=fn>QStringList <a href="#grep-2"><b>grep</b></a> ( const QRegExp & expr ) const</div></li> </ul> <h2>Static Public Members</h2> <ul> <li><div class=fn>QStringList <a href="#fromStrList"><b>fromStrList</b></a> ( const QStrList & ascii )</div></li> <li><div class=fn>QStringList <a href="#split-2"><b>split</b></a> ( const QString & sep, const QString & str, bool allowEmptyEntries = FALSE )</div></li> <li><div class=fn>QStringList <a href="#split-3"><b>split</b></a> ( const QChar & sep, const QString & str, bool allowEmptyEntries = FALSE )</div></li> <li><div class=fn>QStringList <a href="#split"><b>split</b></a> ( const QRegExp & sep, const QString & str, bool allowEmptyEntries = FALSE )</div></li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The QStringList class provides a list of strings. <p> <p> It is used to store and manipulate strings that logically belong together. Essentially QStringList is a <a href="qvaluelist.html">QValueList</a> of <a href="qstring.html">QString</a> objects. Unlike <a href="qstrlist.html">QStrList</a>, which stores pointers to characters, QStringList holds real QString objects. It is the class of choice whenever you work with Unicode strings. QStringList is part of the <a href="qtl.html">Qt Template Library</a>. <p> Like QString itself, QStringList objects are <a href="shclass.html#implicitly-shared">implicitly shared</a>. Passing them around as value-parameters is both fast and safe. <p> Strings can be added to a list using <a href="qvaluelist.html#append">append</a>(), <a href="qvaluelist.html#operator+-eq">operator+=</a>() or <a href="qvaluelist.html#operator-lt-lt">operator<<</a>(), e.g. <pre> QStringList fonts; fonts.<a href="qvaluelist.html#append">append</a>( "Times" ); fonts += "Courier"; fonts += "Courier New"; fonts << "Helvetica [Cronyx]" << "Helvetica [Adobe]"; </pre> <p> String lists have an iterator, QStringList::Iterator(), e.g. <pre> for ( QStringList::<a href="qvaluelist.html#Iterator">Iterator</a> it = fonts.begin(); it != fonts.end(); ++it ) { cout << *it << ":"; } cout << endl; // Output: // Times:Courier:Courier New:Helvetica [Cronyx]:Helvetica [Adobe]: </pre> <p> Many Qt functions return const string lists; to iterate over these you should make a copy and iterate over the copy. <p> You can concatenate all the strings in a string list into a single string (with an optional separator) using <a href="#join">join</a>(), e.g. <pre> <a href="qstring.html">QString</a> allFonts = fonts.join( ", " ); cout << allFonts << endl; // Output: // Times, Courier, Courier New, Helvetica [Cronyx], Helvetica [Adobe] </pre> <p> You can sort the list with <a href="#sort">sort</a>(), and extract a new list which contains only those strings which contain a particular substring (or match a particular <a href="qregexp.html#regular-expression">regular expression</a>) using the <a href="#grep">grep</a>() functions, e.g. <pre> fonts.sort(); cout << fonts.join( ", " ) << endl; // Output: // Courier, Courier New, Helvetica [Adobe], Helvetica [Cronyx], Times QStringList helveticas = fonts.grep( "Helvetica" ); cout << helveticas.<a href="#join">join</a>( ", " ) << endl; // Output: // Helvetica [Adobe], Helvetica [Cronyx] </pre> <p> Existing strings can be split into string lists with character, string or regular expression separators, e.g. <pre> <a href="qstring.html">QString</a> s = "Red\tGreen\tBlue"; QStringList colors = QStringList::<a href="#split">split</a>( "\t", s ); cout << colors.<a href="#join">join</a>( ", " ) << endl; // Output: // Red, Green, Blue </pre> <p>See also <a href="shared.html">Implicitly and Explicitly Shared Classes</a>, <a href="text.html">Text Related Classes</a>, and <a href="tools.html">Non-GUI Classes</a>. <hr><h2>Member Function Documentation</h2> <h3 class=fn><a name="QStringList"></a>QStringList::QStringList () </h3> <p> Creates an empty string list. <h3 class=fn><a name="QStringList-2"></a>QStringList::QStringList ( const <a href="qstringlist.html">QStringList</a> & l ) </h3> <p> Creates a copy of the list <em>l</em>. This function is very fast because QStringList is <a href="shclass.html#implicitly-shared">implicitly shared</a>. In most situations this acts like a <a href="shclass.html#deep-copy">deep copy</a>, for example, if this list or the original one or some other list referencing the same shared data is modified, the modifying list first makes a copy, i.e. copy-on-write. In a threaded environment you may require a real deep copy . <h3 class=fn><a name="QStringList-3"></a>QStringList::QStringList ( const <a href="qvaluelist.html">QValueList</a><QString> & l ) </h3> <p> Constructs a new string list that is a copy of <em>l</em>. <h3 class=fn><a name="QStringList-4"></a>QStringList::QStringList ( const <a href="qstring.html">QString</a> & i ) </h3> <p> Constructs a string list consisting of the single string <em>i</em>. Longer lists are easily created as follows: <p> <pre> QStringList items; items << "Buy" << "Sell" << "Update" << "Value"; </pre> <h3 class=fn><a name="QStringList-5"></a>QStringList::QStringList ( const char * i ) </h3> <p> Constructs a string list consisting of the single latin-1 string <em>i</em>. <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="fromStrList"></a>QStringList::fromStrList ( const <a href="qstrlist.html">QStrList</a> & ascii )<tt> [static]</tt> </h3> Converts from an ASCII-QStrList <em>ascii</em> to a QStringList (Unicode). <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="grep"></a>QStringList::grep ( const <a href="qstring.html">QString</a> & str, bool cs = TRUE ) const </h3> Returns a list of all strings containing the substring <em>str</em>. <p> If <em>cs</em> is TRUE, the grep is done case-sensitively; otherwise case is ignored. <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="grep-2"></a>QStringList::grep ( const <a href="qregexp.html">QRegExp</a> & expr ) const </h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function. <p> Returns a list of all the strings that match the <a href="qregexp.html#regular-expression">regular expression</a> <em>expr</em>. <h3 class=fn><a href="qstring.html">QString</a> <a name="join"></a>QStringList::join ( const <a href="qstring.html">QString</a> & sep ) const </h3> Joins the string list into a single string with each element separated by the string <em>sep</em> (which can be empty). <p> <p>See also <a href="#split">split</a>(). <h3 class=fn>void <a name="sort"></a>QStringList::sort () </h3> Sorts the list of strings in ascending case-sensitive order. <p> Sorting is very fast. It uses the <a href="qtl.html">Qt Template Library's</a> efficient HeapSort implementation that has a time complexity of O(n*log n). <p> If you want to sort your strings in an arbitrary order consider using a <a href="qmap.html">QMap</a>. For example you could use a QMap<QString,QString> to create a case-insensitive ordering (e.g. mapping the lowercase text to the text), or a QMap<int,QString> to sort the strings by some integer index, etc. <p>Example: <a href="themes-example.html#x339">themes/themes.cpp</a>. <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="split"></a>QStringList::split ( const <a href="qregexp.html">QRegExp</a> & sep, const <a href="qstring.html">QString</a> & str, bool allowEmptyEntries = FALSE )<tt> [static]</tt> </h3> Splits the string <em>str</em> into strings wherever the <a href="qregexp.html#regular-expression">regular expression</a> <em>sep</em> occurs, and returns the list of those strings. <p> If <em>allowEmptyEntries</em> is TRUE, an empty string is inserted in the list wherever the separator matches twice without intervening text. <p> For example, if you split the string "a,,b,c" on commas, <a href="#split">split</a>() returns the three-item list "a", "b", "c" if <em>allowEmptyEntries</em> is FALSE (the default), and the four-item list "a", "", "b", "c" if <em>allowEmptyEntries</em> is TRUE. <p> If <em>sep</em> does not match anywhere in <em>str</em>, split() returns a list consisting of the single string <em>str</em>. <p> <p>See also <a href="#join">join</a>() and <a href="qstring.html#section">QString::section</a>(). <p>Examples: <a href="tutorial2-03.html#x2599">chart/element.cpp</a>, <a href="dirview-example.html#x1772">dirview/dirview.cpp</a>, and <a href="httpd-example.html#x647">network/httpd/httpd.cpp</a>. <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="split-2"></a>QStringList::split ( const <a href="qstring.html">QString</a> & sep, const <a href="qstring.html">QString</a> & str, bool allowEmptyEntries = FALSE )<tt> [static]</tt> </h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function. <p> This version of the function uses a <a href="qstring.html">QString</a> as separator, rather than a <a href="qregexp.html#regular-expression">regular expression</a>. <p> If <em>sep</em> is an empty string, the return value is a list of one-character strings: <a href="#split">split</a>( QString( "" ), "four" ) returns the four-item list, "f", "o", "u", "r". <p> If <em>allowEmptyEntries</em> is TRUE, an empty string is inserted in the list wherever the separator matches twice without intervening text. <p> <p>See also <a href="#join">join</a>() and <a href="qstring.html#section">QString::section</a>(). <h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="split-3"></a>QStringList::split ( const <a href="qchar.html">QChar</a> & sep, const <a href="qstring.html">QString</a> & str, bool allowEmptyEntries = FALSE )<tt> [static]</tt> </h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function. <p> This version of the function uses a <a href="qchar.html">QChar</a> as separator, rather than a <a href="qregexp.html#regular-expression">regular expression</a>. <p> <p>See also <a href="#join">join</a>() and <a href="qstring.html#section">QString::section</a>(). <!-- eof --> <hr><p> This file is part of the <a href="index.html">Qt toolkit</a>. Copyright © 1995-2002 <a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center> <table width=100% cellspacing=0 border=0><tr> <td>Copyright © 2002 <a href="http://www.trolltech.com">Trolltech</a><td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a> <td align=right><div align=right>Qt version 3.1.1</div> </table></div></address></body> </html>