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---
title: Set.prototype.clear()
slug: Web/JavaScript/Reference/Global_Objects/Set/clear
tags:
- ECMAScript6
- JavaScript
- Prototype
- set
- 原型
- 方法
translation_of: Web/JavaScript/Reference/Global_Objects/Set/clear
---
<div>{{JSRef}}</div>
<p><code><strong>clear()</strong></code> 方法用来清空一个 <code>Set</code> 对象中的所有元素。</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre class="syntaxbox"><code><em>mySet</em>.clear();</code>
</pre>
<h3 id="返回值">返回值</h3>
<p>{{jsxref("undefined")}}.</p>
<h2 id="Examples" name="Examples">示例</h2>
<pre class="brush: js">var mySet = new Set();
mySet.add(1);
mySet.add("foo");
mySet.size; // 2
mySet.has("foo"); // true
mySet.clear();
mySet.size; // 0
mySet.has("bar") // false
</pre>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">Specification</th>
<th scope="col">Status</th>
<th scope="col">Comment</th>
</tr>
<tr>
<td>{{SpecName('ES6', '#sec-set.prototype.clear', 'Set.prototype.clear')}}</td>
<td>{{Spec2('ES6')}}</td>
<td>Initial definition.</td>
</tr>
<tr>
<td>{{SpecName('ESDraft', '#sec-set.prototype.clear', 'Set.prototype.clear')}}</td>
<td>{{Spec2('ESDraft')}}</td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{ CompatibilityTable() }}</p>
<div>
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
</tr>
<tr>
<td>Basic support</td>
<td>38</td>
<td>{{CompatGeckoDesktop("19.0")}}</td>
<td>11</td>
<td>25</td>
<td>7.1</td>
</tr>
</tbody>
</table>
</div>
<div>
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Chrome for 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>{{ CompatNo() }}</td>
<td>25</td>
<td>{{CompatGeckoMobile("19.0")}}</td>
<td>{{ CompatNo() }}</td>
<td>{{ CompatNo() }}</td>
<td>8</td>
</tr>
</tbody>
</table>
</div>
<h2 id="相关链接"><strong>相关链接</strong></h2>
<ul>
<li>{{jsxref("Set")}}</li>
<li>{{jsxref("Set.prototype.delete()")}}</li>
</ul>
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