<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qlist.cpp --> <title>iterator Class | Qt Core 5.12.6</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtcore-index.html">Qt Core</a></td><td ><a href="qtcore-module.html">C++ Classes</a></td><td >iterator</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtcore-index.html">Qt 5.12.6 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-types">Public Types</a></li> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#public-variables">Public Variables</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">iterator Class</h1> <span class="small-subtitle">(<a href="qlist-iterator.html">QList::iterator</a>)<br/></span> <!-- $$$iterator-brief --> <p>The <a href="qlist-iterator.html">QList::iterator</a> class provides an STL-style non-const iterator for <a href="qlist.html">QList</a> and <a href="qqueue.html">QQueue</a>. <a href="#details">More...</a></p> <!-- @@@iterator --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <iterator></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += core</td></tr></table></div><ul> <li><a href="qlist-iterator-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-types"></a> <h2 id="public-types">Public Types</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#iterator_category-typedef">iterator_category</a></b></td></tr> </table></div> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#iterator">iterator</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#iterator-2">iterator</a></b>(const iterator &<i>other</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-not-eq">operator!=</a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-not-eq-1">operator!=</a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> T &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-2a">operator*</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-2b">operator+</a></b>(iterator::difference_type <i>j</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-2b-2b">operator++</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-2b-2b-1">operator++</a></b>(<i>int</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-2b-eq">operator+=</a></b>(iterator::difference_type <i>j</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-">operator-</a></b>(iterator::difference_type <i>j</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator--1">operator-</a></b>(iterator <i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator--">operator--</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator---1">operator--</a></b>(<i>int</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> iterator &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator--eq">operator-=</a></b>(iterator::difference_type <i>j</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> T *</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator--gt">operator-></a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-lt">operator<</a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-lt-1">operator<</a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-lt-eq">operator<=</a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-lt-eq-1">operator<=</a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-eq-eq">operator==</a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-eq-eq-1">operator==</a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-gt">operator></a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-gt-1">operator></a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-gt-eq">operator>=</a></b>(const iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-gt-eq-1">operator>=</a></b>(const const_iterator &<i>other</i>) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> T &</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#operator-5b-5d">operator[]</a></b>(iterator::difference_type <i>j</i>) const</td></tr> </table></div> <a name="public-variables"></a> <h2 id="public-variables">Public Variables</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> QList::Node *</td><td class="memItemRight bottomAlign"><b><a href="qlist-iterator.html#i-var">i</a></b></td></tr> </table></div> <a name="details"></a> <!-- $$$iterator-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qlist-iterator.html">QList::iterator</a> class provides an STL-style non-const iterator for <a href="qlist.html">QList</a> and <a href="qqueue.html">QQueue</a>.</p> <p><a href="qlist.html">QList</a> features both <a href="containers.html#stl-style-iterators">STL-style iterators</a> and <a href="containers.html#java-style-iterators">Java-style iterators</a>. The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.</p> <p><a href="qlist.html">QList</a><T>::iterator allows you to iterate over a <a href="qlist.html">QList</a><T> (or <a href="qqueue.html">QQueue</a><T>) and to modify the list item associated with the iterator. If you want to iterate over a const <a href="qlist.html">QList</a>, use <a href="qlist-const-iterator.html">QList::const_iterator</a> instead. It is generally good practice to use <a href="qlist-const-iterator.html">QList::const_iterator</a> on a non-const <a href="qlist.html">QList</a> as well, unless you need to change the <a href="qlist.html">QList</a> through the iterator. Const iterators are slightly faster, and can improve code readability.</p> <p>The default <a href="qlist-iterator.html">QList::iterator</a> constructor creates an uninitialized iterator. You must initialize it using a <a href="qlist.html">QList</a> function like <a href="qlist.html#begin">QList::begin</a>(), <a href="qlist.html#end">QList::end</a>(), or <a href="qlist.html#insert">QList::insert</a>() before you can start iterating. Here's a typical loop that prints all the items stored in a list:</p> <pre class="cpp"> <span class="type"><a href="qlist.html#QList">QList</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">></span> list; list<span class="operator">.</span>append(<span class="string">"January"</span>); list<span class="operator">.</span>append(<span class="string">"February"</span>); <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> list<span class="operator">.</span>append(<span class="string">"December"</span>); <span class="type"><a href="qlist.html#QList">QList</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">></span><span class="operator">::</span>iterator i; <span class="keyword">for</span> (i <span class="operator">=</span> list<span class="operator">.</span>begin(); i <span class="operator">!</span><span class="operator">=</span> list<span class="operator">.</span>end(); <span class="operator">+</span><span class="operator">+</span>i) cout <span class="operator"><</span><span class="operator"><</span> <span class="operator">*</span>i <span class="operator"><</span><span class="operator"><</span> endl; </pre> <p>Let's see a few examples of things we can do with a <a href="qlist-iterator.html">QList::iterator</a> that we cannot do with a <a href="qlist-const-iterator.html">QList::const_iterator</a>. Here's an example that increments every value stored in a <a href="qlist.html">QList</a><int> by 2:</p> <pre class="cpp"> <span class="type"><a href="qlist.html#QList">QList</a></span><span class="operator"><</span><span class="type">int</span><span class="operator">></span><span class="operator">::</span>iterator i; <span class="keyword">for</span> (i <span class="operator">=</span> list<span class="operator">.</span>begin(); i <span class="operator">!</span><span class="operator">=</span> list<span class="operator">.</span>end(); <span class="operator">+</span><span class="operator">+</span>i) <span class="operator">*</span>i <span class="operator">+</span><span class="operator">=</span> <span class="number">2</span>; </pre> <p>Most <a href="qlist.html">QList</a> functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with <a href="qlist.html">QList</a>. One place where STL-style iterators do make sense is as arguments to <a href="qtalgorithms.html">generic algorithms</a>.</p> <p>For example, here's how to delete all the widgets stored in a <a href="qlist.html">QList</a><<a href="../qtwidgets/qwidget.html">QWidget</a> *>:</p> <pre class="cpp"> <span class="type"><a href="qlist.html#QList">QList</a></span><span class="operator"><</span><span class="type"><a href="../qtwidgets/qwidget.html">QWidget</a></span> <span class="operator">*</span><span class="operator">></span> list; <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> <a href="qtalgorithms.html#qDeleteAll">qDeleteAll</a>(list<span class="operator">.</span>begin()<span class="operator">,</span> list<span class="operator">.</span>end()); </pre> <p>Multiple iterators can be used on the same list. However, be aware that any non-const function call performed on the <a href="qlist.html">QList</a> will render all existing iterators undefined. If you need to keep iterators over a long period of time, we recommend that you use <a href="qlinkedlist.html">QLinkedList</a> rather than <a href="qlist.html">QList</a>.</p> <p><b>Warning:</b> Iterators on implicitly shared containers do not work exactly like STL-iterators. You should avoid copying a container while iterators are active on that container. For more information, read <a href="containers.html#implicit-sharing-iterator-problem">Implicit sharing iterator problem</a>.</p> </div> <p><b>See also </b><a href="qlist-const-iterator.html">QList::const_iterator</a> and <a href="qmutablelistiterator.html">QMutableListIterator</a>.</p> <!-- @@@iterator --> <div class="types"> <h2>Member Type Documentation</h2> <!-- $$$iterator_category --> <h3 class="fn" id="iterator_category-typedef"><a name="iterator_category-typedef"></a>typedef iterator::<span class="name">iterator_category</span></h3> <p>A synonym for <i>std::random_access_iterator_tag</i> indicating this iterator is a random access iterator.</p> <!-- @@@iterator_category --> </div> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-gt-eq"><a name="operator-gt-eq"></a><span class="type">bool</span> iterator::<span class="name">operator>=</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-gt-eq-1"><a name="operator-gt-eq-1"></a><span class="type">bool</span> iterator::<span class="name">operator>=</span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if the item pointed to by this iterator is greater than or equal to the item pointed to by the <i>other</i> iterator.</p> <!-- @@@ --> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-gt"><a name="operator-gt"></a><span class="type">bool</span> iterator::<span class="name">operator></span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-gt-1"><a name="operator-gt-1"></a><span class="type">bool</span> iterator::<span class="name">operator></span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if the item pointed to by this iterator is greater than the item pointed to by the <i>other</i> iterator.</p> <!-- @@@ --> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-lt-eq"><a name="operator-lt-eq"></a><span class="type">bool</span> iterator::<span class="name">operator<=</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-lt-eq-1"><a name="operator-lt-eq-1"></a><span class="type">bool</span> iterator::<span class="name">operator<=</span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if the item pointed to by this iterator is less than or equal to the item pointed to by the <i>other</i> iterator.</p> <!-- @@@ --> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-lt"><a name="operator-lt"></a><span class="type">bool</span> iterator::<span class="name">operator<</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-lt-1"><a name="operator-lt-1"></a><span class="type">bool</span> iterator::<span class="name">operator<</span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if the item pointed to by this iterator is less than the item pointed to by the <i>other</i> iterator.</p> <!-- @@@ --> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-not-eq"><a name="operator-not-eq"></a><span class="type">bool</span> iterator::<span class="name">operator!=</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-not-eq-1"><a name="operator-not-eq-1"></a><span class="type">bool</span> iterator::<span class="name">operator!=</span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if <i>other</i> points to a different item than this iterator; otherwise returns <code>false</code>.</p> <p><b>See also </b><a href="qlist-iterator.html#operator-eq-eq">operator==</a>().</p> <!-- @@@ --> <!-- $$$ --> <div class="fngroup"> <h3 class="fn fngroupitem" id="operator-eq-eq"><a name="operator-eq-eq"></a><span class="type">bool</span> iterator::<span class="name">operator==</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>) const</h3><h3 class="fn fngroupitem" id="operator-eq-eq-1"><a name="operator-eq-eq-1"></a><span class="type">bool</span> iterator::<span class="name">operator==</span>(const <span class="type"><a href="qlist-const-iterator.html">const_iterator</a></span> &<i>other</i>) const</h3></div> <p>Returns <code>true</code> if <i>other</i> points to the same item as this iterator; otherwise returns <code>false</code>.</p> <p><b>See also </b><a href="qlist-iterator.html#operator-not-eq">operator!=</a>().</p> <!-- @@@ --> <!-- $$$iterator[overload1]$$$iterator --> <h3 class="fn" id="iterator"><a name="iterator"></a>iterator::<span class="name">iterator</span>()</h3> <p>Constructs an uninitialized iterator.</p> <p>Functions like operator*() and operator++() should not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.</p> <p><b>See also </b><a href="qlist.html#begin">QList::begin</a>() and <a href="qlist.html#end">QList::end</a>().</p> <!-- @@@iterator --> <!-- $$$iterator$$$iteratorconstiterator& --> <h3 class="fn" id="iterator-2"><a name="iterator-2"></a>iterator::<span class="name">iterator</span>(const <span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &<i>other</i>)</h3> <p>Constructs a copy of <i>other</i>.</p> <!-- @@@iterator --> <!-- $$$operator*[overload1]$$$operator* --> <h3 class="fn" id="operator-2a"><a name="operator-2a"></a><span class="type">T</span> &iterator::<span class="name">operator*</span>() const</h3> <p>Returns a modifiable reference to the current item.</p> <p>You can change the value of an item by using operator*() on the left side of an assignment, for example:</p> <pre class="cpp"> <span class="keyword">if</span> (<span class="operator">*</span>it <span class="operator">=</span><span class="operator">=</span> <span class="string">"Hello"</span>) <span class="operator">*</span>it <span class="operator">=</span> <span class="string">"Bonjour"</span>; </pre> <p><b>See also </b><a href="qlist-iterator.html#operator--gt">operator-></a>().</p> <!-- @@@operator* --> <!-- $$$operator+[overload1]$$$operator+iterator::difference_type --> <h3 class="fn" id="operator-2b"><a name="operator-2b"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> iterator::<span class="name">operator+</span>(<span class="type">iterator::difference_type</span> <i>j</i>) const</h3> <p>Returns an iterator to the item at <i>j</i> positions forward from this iterator. (If <i>j</i> is negative, the iterator goes backward.)</p> <p><b>See also </b><a href="qlist-iterator.html#operator-">operator-</a>() and <a href="qlist-iterator.html#operator-2b-eq">operator+=</a>().</p> <!-- @@@operator+ --> <!-- $$$operator++[overload1]$$$operator++ --> <h3 class="fn" id="operator-2b-2b"><a name="operator-2b-2b"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &iterator::<span class="name">operator++</span>()</h3> <p>The prefix ++ operator (<code>++it</code>) advances the iterator to the next item in the list and returns an iterator to the new current item.</p> <p>Calling this function on <a href="qlist.html#end">QList::end</a>() leads to undefined results.</p> <p><b>See also </b><a href="qlist-iterator.html#operator--">operator--</a>().</p> <!-- @@@operator++ --> <!-- $$$operator++$$$operator++int --> <h3 class="fn" id="operator-2b-2b-1"><a name="operator-2b-2b-1"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> iterator::<span class="name">operator++</span>(<i>int</i>)</h3> <p>This is an overloaded function.</p> <p>The postfix ++ operator (<code>it++</code>) advances the iterator to the next item in the list and returns an iterator to the previously current item.</p> <!-- @@@operator++ --> <!-- $$$operator+=[overload1]$$$operator+=iterator::difference_type --> <h3 class="fn" id="operator-2b-eq"><a name="operator-2b-eq"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &iterator::<span class="name">operator+=</span>(<span class="type">iterator::difference_type</span> <i>j</i>)</h3> <p>Advances the iterator by <i>j</i> items. (If <i>j</i> is negative, the iterator goes backward.)</p> <p><b>See also </b><a href="qlist-iterator.html#operator--eq">operator-=</a>() and <a href="qlist-iterator.html#operator-2b">operator+</a>().</p> <!-- @@@operator+= --> <!-- $$$operator-[overload1]$$$operator-iterator::difference_type --> <h3 class="fn" id="operator-"><a name="operator-"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> iterator::<span class="name">operator-</span>(<span class="type">iterator::difference_type</span> <i>j</i>) const</h3> <p>Returns an iterator to the item at <i>j</i> positions backward from this iterator. (If <i>j</i> is negative, the iterator goes forward.)</p> <p><b>See also </b><a href="qlist-iterator.html#operator-2b">operator+</a>() and <a href="qlist-iterator.html#operator--eq">operator-=</a>().</p> <!-- @@@operator- --> <!-- $$$operator-$$$operator-iterator --> <h3 class="fn" id="operator--1"><a name="operator--1"></a><span class="type">int</span> iterator::<span class="name">operator-</span>(<span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> <i>other</i>) const</h3> <p>Returns the number of items between the item pointed to by <i>other</i> and the item pointed to by this iterator.</p> <!-- @@@operator- --> <!-- $$$operator--[overload1]$$$operator-- --> <h3 class="fn" id="operator--"><a name="operator--"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &iterator::<span class="name">operator--</span>()</h3> <p>The prefix -- operator (<code>--it</code>) makes the preceding item current and returns an iterator to the new current item.</p> <p>Calling this function on <a href="qlist.html#begin">QList::begin</a>() leads to undefined results.</p> <p><b>See also </b><a href="qlist-iterator.html#operator-2b-2b">operator++</a>().</p> <!-- @@@operator-- --> <!-- $$$operator--$$$operator--int --> <h3 class="fn" id="operator---1"><a name="operator---1"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> iterator::<span class="name">operator--</span>(<i>int</i>)</h3> <p>This is an overloaded function.</p> <p>The postfix -- operator (<code>it--</code>) makes the preceding item current and returns an iterator to the previously current item.</p> <!-- @@@operator-- --> <!-- $$$operator-=[overload1]$$$operator-=iterator::difference_type --> <h3 class="fn" id="operator--eq"><a name="operator--eq"></a><span class="type"><a href="qlist-iterator.html#iterator">iterator</a></span> &iterator::<span class="name">operator-=</span>(<span class="type">iterator::difference_type</span> <i>j</i>)</h3> <p>Makes the iterator go back by <i>j</i> items. (If <i>j</i> is negative, the iterator goes forward.)</p> <p><b>See also </b><a href="qlist-iterator.html#operator-2b-eq">operator+=</a>() and <a href="qlist-iterator.html#operator-">operator-</a>().</p> <!-- @@@operator-= --> <!-- $$$operator->[overload1]$$$operator-> --> <h3 class="fn" id="operator--gt"><a name="operator--gt"></a><span class="type">T</span> *iterator::<span class="name">operator-></span>() const</h3> <p>Returns a pointer to the current item.</p> <p><b>See also </b><a href="qlist-iterator.html#operator-2a">operator*</a>().</p> <!-- @@@operator-> --> <!-- $$$operator[][overload1]$$$operator[]iterator::difference_type --> <h3 class="fn" id="operator-5b-5d"><a name="operator-5b-5d"></a><span class="type">T</span> &iterator::<span class="name">operator[]</span>(<span class="type">iterator::difference_type</span> <i>j</i>) const</h3> <p>Returns a modifiable reference to the item at position *this + <i>j</i>.</p> <p>This function is provided to make <a href="qlist.html">QList</a> iterators behave like C++ pointers.</p> <p><b>See also </b><a href="qlist-iterator.html#operator-2b">operator+</a>().</p> <!-- @@@operator[] --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>