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---
title: Element.childElementCount
slug: Web/API/Element/childElementCount
translation_of: Web/API/Element/childElementCount
tags:
- API
- DOM
- Property
- Reference
browser-compat: api.Element.childElementCount
---
<p>{{ APIRef("DOM") }} </p>
<p> <code><strong>Element.childElementCount </strong></code>只读属性返回一个<em><strong>无符号长整型数字</strong></em>，表示给定元素的子元素数。</p>
<div class="note">
<p>This property was initially defined in the {{domxref("ElementTraversal")}} pure interface. As this interface contained two distinct set of properties, one aimed at {{domxref("Node")}} that have children, one at those that are children, they have been moved into two separate pure interfaces, {{domxref("Element")}} and {{domxref("ChildNode")}}. In this case, <code>childElementCount</code> moved to {{domxref("Element")}}. This is a fairly technical change that shouldn't affect compatibility.</p>
</div>
<p> </p>
<h2 id="Syntax_and_values" name="Syntax_and_values">语法</h2>
<pre>var <var>count</var> = <em>node</em>.childElementCount;</pre>
<pre class="eval">var <em>elCount</em> = elementNodeReference.childElementCount;
</pre>
<dl>
<dt>count</dt>
<dd>holds the return value an <code>unsigned long </code>(simply an integer) type.</dd>
<dt>node</dt>
<dd>is an object representing a <code>Document</code>, <code>DocumentFragment</code> or <code>Element</code>.</dd>
</dl>
<h2 id="例子">例子</h2>
<pre><code>var foo = document.getElementById("foo");
if (foo.childElementCount > 0) {
// do something
}</code></pre>
<p>下例演示了一个元素节点的<code>childElementCount</code>属性以及<code>children</code>属性的用法.</p>
<pre class="eval"><head>
<script type="text/javascript">
function GetChildCount () {
var container = document.getElementById ("container");
var childCount = 0;
//如果支持childElementCount属性
if ('childElementCount' in container) {
childCount = container.childElementCount;
}
else {
//如果支持children属性,IE6/7/8
//译者注:没有判断nodeType是否为1,可能包含注释节点.
if (container.children) {
childCount = container.children.length;
}
else { //,如果都不支持,Firefox 3.5之前版本
var child = container.firstChild;
while (child) {
if (child.nodeType == 1 /*Node.ELEMENT_NODE*/) {
childCount++;
}
child = child.nextSibling;
}
}
}
alert ("The number of child elements is " + childCount);
}
</script>
</head>
<body>
<div id="container" style="width:300px; background-color:#a0d0e0;">
Some text inside the container.
<input type="text" size="40" value="a child element of the container" />
<div>
<div>a descendant element of the container</div>
<div>another descendant element of the container</div>
</div>
</div>
<br /><br />
<button onclick="GetChildCount ();">Get the number of container's child elements</button>
</body>
</pre>
<div>执行上面的例子:<a class="external" href="http://help.dottoro.com/external/examples/ljsfamht/childElementCount_1.htm">http://help.dottoro.com/external/examples/ljsfamht/childElementCount_1.htm</a></div>
<p> </p>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{ CompatibilityTable() }}</p>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Firefox (Gecko)</th>
<th>Chrome</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{ CompatGeckoDesktop("3") }}</td>
<td>{{ CompatVersionUnknown() }}</td>
<td>9.0</td>
<td>{{ CompatVersionUnknown() }}</td>
<td>{{ CompatVersionUnknown() }}</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Firefox Mobile (Gecko)</th>
<th>IE Mobile</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
</tr>
<tr>
<td>Basic support</td>
<td>?</td>
<td>?</td>
<td>?</td>
<td>?</td>
<td>?</td>
</tr>
</tbody>
</table>
</div>
<h2 id="Specification" name="Specification">规范</h2>
<p><a href="http://www.w3.org/TR/2008/WD-ElementTraversal-20080303/#attribute-childElementCount" rel="nofollow">childElementCount (W3C)</a></p>
<h2 id="相关链接">相关链接</h2>
<ul>
<li><a class="internal" href="/zh-cn/DOM/Element.children" title="zh-cn/DOM/Element.children"><code>children</code></a></li>
<li><a class="internal" href="/zh-cn/DOM/Element.firstElementChild" title="zh-cn/DOM/Element.firstElementChild"><code>firstElementChild</code></a></li>
<li><a class="internal" href="/zh-cn/DOM/Element.lastElementChild" title="zh-cn/DOM/Element.lastElementChild"><code>lastElementChild</code></a></li>
<li><a class="internal" href="/zh-cn/DOM/Element.nextElementSibling" title="zh-cn/DOM/Element.nextElementSibling"><code>nextElementSibling</code></a></li>
<li><a class="internal" href="/zh-cn/DOM/element.previousElementSibling" title="zh-cn/DOM/Element.previousElementSibling"><code>previousElementSibling</code></a></li>
</ul>
<p> </p>
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