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Revision 641513 of Set.prototype.clear()

  • Revision slug: Web/JavaScript/Reference/Global_Objects/Set/clear
  • Revision title: Set.prototype.clear()
  • Revision id: 641513
  • Created:
  • Creator: ziyunfei
  • Is current revision? No
  • Comment

Revision Content

{{JSRef("Global_Objects", "Set")}} {{harmony}}

概述

clear() 方法用来清空一个 Set 对象的所有元素。

语法

mySet.clear();

示例

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

规范

Specification Status Comment
{{SpecName('ES6', '#sec-set.prototype.clear', 'Set.prototype.clear')}} {{Spec2('ES6')}} Initial definition.

浏览器兼容性

{{ CompatibilityTable() }}

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 31 {{CompatGeckoDesktop("19.0")}} 11 {{ CompatNo() }} {{ CompatNo() }}
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support {{ CompatNo() }} {{ CompatNo() }} {{CompatGeckoMobile("19.0")}} {{ CompatNo() }} {{ CompatNo() }} {{ CompatNo() }}

相关链接

  • {{jsxref("Set")}}
  • {{jsxref("Set.prototype.delete()")}}

Revision Source

<div>
 {{JSRef("Global_Objects", "Set")}} {{harmony}}</div>
<h2 id="Summary" name="Summary">概述</h2>
<p><code><strong>clear()</strong></code> 方法用来清空一个 <code>Set</code> 对象的所有元素。</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre class="syntaxbox">
<code><em>mySet</em>.clear();</code></pre>
<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="Specifications">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>
 </tbody>
</table>
<h2 id="Browser_compatibility">浏览器兼容性</h2>
<p>{{ CompatibilityTable() }}</p>
<div id="compat-desktop">
 <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>31</td>
    <td>{{CompatGeckoDesktop("19.0")}}</td>
    <td>11</td>
    <td>{{ CompatNo() }}</td>
    <td>{{ CompatNo() }}</td>
   </tr>
  </tbody>
 </table>
</div>
<div id="compat-mobile">
 <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>{{ CompatNo() }}</td>
    <td>{{CompatGeckoMobile("19.0")}}</td>
    <td>{{ CompatNo() }}</td>
    <td>{{ CompatNo() }}</td>
    <td>{{ CompatNo() }}</td>
   </tr>
  </tbody>
 </table>
</div>
<h3 id="Chrome-specific_notes"><span style="font-size: 2.14285714285714rem; font-weight: 700; letter-spacing: -1px; line-height: 30px;">相关链接</span></h3>
<ul>
 <li>{{jsxref("Set")}}</li>
 <li>{{jsxref("Set.prototype.delete()")}}</li>
</ul>
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