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<td >Qt 5.9</td><td ><a href="qtcore-index.html">Qt Core</a></td><td ><a href="qtcore-module.html">C++ Classes</a></td><td >QAssociativeIterable</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td>
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<h3><a name="toc">Contents</a></h3>
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<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="#details">Detailed Description</a></li>
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<h1 class="title">QAssociativeIterable Class</h1>
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<p>The <a href="qassociativeiterable.html">QAssociativeIterable</a> class is an iterable interface for an associative container in a <a href="qvariant.html">QVariant</a>. <a href="#details">More...</a></p>
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<tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QAssociativeIterable></span>
</td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += core</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 5.2</td></tr></table></div><ul>
<li><a href="qassociativeiterable-members.html">List of all members, including inherited members</a></li>
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<a name="public-types"></a>
<h2 id="public-types">Public Types</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> class </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable-const-iterator.html">const_iterator</a></b></td></tr>
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<h2 id="public-functions">Public Functions</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable.html#begin">begin</a></b>() const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable.html#end">end</a></b>() const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable.html#find">find</a></b>(const QVariant &<i>key</i>) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable.html#size">size</a></b>() const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QVariant </td><td class="memItemRight bottomAlign"><b><a href="qassociativeiterable.html#value">value</a></b>(const QVariant &<i>key</i>) const</td></tr>
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<a name="details"></a>
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<h2 id="details">Detailed Description</h2>
<p>The <a href="qassociativeiterable.html">QAssociativeIterable</a> class is an iterable interface for an associative container in a <a href="qvariant.html">QVariant</a>.</p>
<p>This class allows several methods of accessing the elements of an associative container held within a <a href="qvariant.html">QVariant</a>. An instance of <a href="qassociativeiterable.html">QAssociativeIterable</a> can be extracted from a <a href="qvariant.html">QVariant</a> if it can be converted to a <a href="qvariant.html#QVariantHash-typedef">QVariantHash</a> or <a href="qvariant.html#QVariantMap-typedef">QVariantMap</a>.</p>
<pre class="cpp">
<span class="type"><a href="qhash.html">QHash</a></span><span class="operator"><</span><span class="type">int</span><span class="operator">,</span> <span class="type"><a href="qstring.html">QString</a></span><span class="operator">></span> mapping;
mapping<span class="operator">.</span>insert(<span class="number">7</span><span class="operator">,</span> <span class="string">"Seven"</span>);
mapping<span class="operator">.</span>insert(<span class="number">11</span><span class="operator">,</span> <span class="string">"Eleven"</span>);
mapping<span class="operator">.</span>insert(<span class="number">42</span><span class="operator">,</span> <span class="string">"Forty-two"</span>);
<span class="type"><a href="qvariant.html">QVariant</a></span> variant <span class="operator">=</span> <span class="type"><a href="qvariant.html">QVariant</a></span><span class="operator">::</span>fromValue(mapping);
<span class="keyword">if</span> (variant<span class="operator">.</span>canConvert<span class="operator"><</span><span class="type"><a href="qvariant.html#QVariantHash-typedef">QVariantHash</a></span><span class="operator">></span>()) {
<span class="type">QAssociativeIterable</span> iterable <span class="operator">=</span> variant<span class="operator">.</span>value<span class="operator"><</span><span class="type">QAssociativeIterable</span><span class="operator">></span>();
<span class="comment">// Can use foreach over the values:</span>
foreach (<span class="keyword">const</span> <span class="type"><a href="qvariant.html">QVariant</a></span> <span class="operator">&</span>v<span class="operator">,</span> iterable) {
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> v;
}
<span class="comment">// Can use C++11 range-for over the values:</span>
<span class="keyword">for</span> (<span class="keyword">const</span> <span class="type"><a href="qvariant.html">QVariant</a></span> <span class="operator">&</span>v : iterable) {
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> v;
}
<span class="comment">// Can use iterators:</span>
<span class="type">QAssociativeIterable</span><span class="operator">::</span>const_iterator it <span class="operator">=</span> iterable<span class="operator">.</span>begin();
<span class="keyword">const</span> <span class="type">QAssociativeIterable</span><span class="operator">::</span>const_iterator end <span class="operator">=</span> iterable<span class="operator">.</span>end();
<span class="keyword">for</span> ( ; it <span class="operator">!</span><span class="operator">=</span> end; <span class="operator">+</span><span class="operator">+</span>it) {
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="operator">*</span>it; <span class="comment">// The current value</span>
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> it<span class="operator">.</span>key();
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> it<span class="operator">.</span>value();
}
}
</pre>
<p>The container itself is not copied before iterating over it.</p>
</div>
<p><b>See also </b><a href="qvariant.html">QVariant</a>.</p>
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<div class="func">
<h2>Member Function Documentation</h2>
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<h3 class="fn" id="begin"><a name="begin"></a><span class="type"><a href="qassociativeiterable-const-iterator.html">const_iterator</a></span> QAssociativeIterable::<span class="name">begin</span>() const</h3>
<p>Returns a <a href="qassociativeiterable-const-iterator.html">QAssociativeIterable::const_iterator</a> for the beginning of the container. This can be used in stl-style iteration.</p>
<p><b>See also </b><a href="qassociativeiterable.html#end">end</a>().</p>
<!-- @@@begin -->
<!-- $$$end[overload1]$$$end -->
<h3 class="fn" id="end"><a name="end"></a><span class="type"><a href="qassociativeiterable-const-iterator.html">const_iterator</a></span> QAssociativeIterable::<span class="name">end</span>() const</h3>
<p>Returns a <a href="qassociativeiterable-const-iterator.html">QAssociativeIterable::const_iterator</a> for the end of the container. This can be used in stl-style iteration.</p>
<p><b>See also </b><a href="qassociativeiterable.html#begin">begin</a>().</p>
<!-- @@@end -->
<!-- $$$find[overload1]$$$findconstQVariant& -->
<h3 class="fn" id="find"><a name="find"></a><span class="type"><a href="qassociativeiterable-const-iterator.html">const_iterator</a></span> QAssociativeIterable::<span class="name">find</span>(const <span class="type"><a href="qvariant.html">QVariant</a></span> &<i>key</i>) const</h3>
<p>Returns a <a href="qassociativeiterable-const-iterator.html">QAssociativeIterable::const_iterator</a> for the given key <i>key</i> in the container, if the types are convertible.</p>
<p>If the key is not found, returns <a href="qassociativeiterable.html#end">end</a>().</p>
<p>This can be used in stl-style iteration.</p>
<p>This function was introduced in Qt 5.5.</p>
<p><b>See also </b><a href="qassociativeiterable.html#begin">begin</a>(), <a href="qassociativeiterable.html#end">end</a>(), and <a href="qassociativeiterable.html#value">value</a>().</p>
<!-- @@@find -->
<!-- $$$size[overload1]$$$size -->
<h3 class="fn" id="size"><a name="size"></a><span class="type">int</span> QAssociativeIterable::<span class="name">size</span>() const</h3>
<p>Returns the number of elements in the container.</p>
<!-- @@@size -->
<!-- $$$value[overload1]$$$valueconstQVariant& -->
<h3 class="fn" id="value"><a name="value"></a><span class="type"><a href="qvariant.html">QVariant</a></span> QAssociativeIterable::<span class="name">value</span>(const <span class="type"><a href="qvariant.html">QVariant</a></span> &<i>key</i>) const</h3>
<p>Returns the value for the given <i>key</i> in the container, if the types are convertible.</p>
<p><b>See also </b><a href="qassociativeiterable.html#find">find</a>().</p>
<!-- @@@value -->
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