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---
title: ':scope'
slug: 'Web/CSS/:scope'
tags:
- ':scope'
- CSS
- Layout
- Pseudo-class
- Reference
- Scoped Elements
- Web
translation_of: 'Web/CSS/:scope'
---
<p>{{CSSRef}}</p>
<p><strong><code>:scope</code></strong> 属于 <a href="/zh-CN/docs/Web/CSS">CSS</a> <a href="/zh-CN/docs/Web/CSS/Pseudo-classes">伪类</a>，它表示作为选择器要匹配的参考点的元素。</p>
<pre class="brush: css">/* Selects a scoped element */
:scope {
background-color: lime;
}</pre>
<p>当前，在样式表中使用时, <code>:scope</code> 等效于 {{cssxref(":root")}}，因为目前尚无一种方法来显式建立作用域元素。当从DOM API使用，如（{{domxref("Element.querySelector", "querySelector()")}}, {{domxref("Element.querySelectorAll", "querySelectorAll()")}}, {{domxref("Element.matches", "matches()")}}, 或 {{domxref("Element.closest()")}}）, <code>:scope</code> 匹配你调用API的元素。</p>
<h2 id="用法">用法</h2>
{{csssyntax}}
<h2 id="示例">示例</h2>
<h3 id="Identity_match">Identity match</h3>
<p>在这个简单的示例中，我们演示了调用 {{domxref("Element.matches()")}} 方法中使用 <code>:scope</code> 伪类来匹配调用它的元素。</p>
<h4 id="JavaScript">JavaScript</h4>
<pre class="brush: js">let paragraph = document.getElementById("para");
let output = document.getElementById("output");
if (paragraph.matches(":scope")) {
output.innerText = "Yep, the element is its own scope as expected!";
}</pre>
<h4 id="HTML">HTML</h4>
<pre class="brush: html"><p id="para">
This is a paragraph. It is not an interesting paragraph. Sorry about that.
</p>
<p id="output"></p></pre>
<h4 id="结果">结果</h4>
<div>{{ EmbedLiveSample('Identity_match') }}</div>
<h3 id="Direct_children">Direct children</h3>
<p>当需要获取已检索到的的直接后代元素时，<code>:scope</code> 伪类很有用。</p>
<h4 id="JavaScript_2">JavaScript</h4>
<pre class="brush: js">var context = document.getElementById('context');
var selected = context.querySelectorAll(':scope > div');
document.getElementById('results').innerHTML = Array.prototype.map.call(selected, function (element) {
return '#' + element.getAttribute('id');
}).join(', ');</pre>
<h4 id="HTML_2">HTML</h4>
<pre class="brush: html"><div id="context">
<div id="element-1">
<div id="element-1.1"></div>
<div id="element-1.2"></div>
</div>
<div id="element-2">
<div id="element-2.1"></div>
</div>
</div>
<p>
Selected elements ids :
<span id="results"></span>
</p></pre>
<h4 id="结果_2">结果</h4>
<p>{{ EmbedLiveSample('Direct_children') }}</p>
<h2 id="规范">规范</h2>
<table class="standard-table">
<thead>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">备注</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{ SpecName('CSS4 Selectors', '#the-scope-pseudo', ':scope') }}</td>
<td>{{ Spec2('CSS4 Selectors') }}</td>
<td>Initial definition.</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>
<div class="hidden">该浏览器兼容性表格由结构化数据生成。如果你愿意做出贡献，可以访问 <a class="external" href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> 和提交PR。</div>
<p>{{Compat("css.selectors.scope")}}</p>
<h2 id="参考">参考</h2>
<ul>
<li>{{cssxref(":root")}} 与 {{cssxref("Pseudo-classes")}}</li>
<li><a href="/zh-CN/docs/Web/API/Document_object_model/Locating_DOM_elements_using_selectors">使用选择器定位DOM元素</a></li>
<li>{{domxref("Element.querySelector()")}} 与 {{domxref("Element.querySelectorAll()")}}</li>
<li>{{domxref("Document.querySelector()")}} 与 {{domxref("Document.querySelectorAll()")}}</li>
<li>{{domxref("DocumentFragment.querySelector()")}} 与 {{domxref("DocumentFragment.querySelectorAll()")}}</li>
<li>{{domxref("ParentNode.querySelector()")}} 与 {{domxref("ParentNode.querySelectorAll()")}}</li>
</ul>
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