---
title: Map.prototype.clear()
slug: Web/JavaScript/Reference/Global_Objects/Map/clear
tags:
  - ECMAScript 2015
  - JavaScript
  - Map
  - Method
  - Prototype
  - Reference
translation_of: Web/JavaScript/Reference/Global_Objects/Map/clear
original_slug: Web/JavaScript/Reference/Global_Objects/Map/clear
browser-compat: javascript.builtins.Map.clear
---
<div>{{JSRef}}</div>

<p><code>clear()</code>方法会移除Map对象中的所有元素。</p>

<div>{{EmbedInteractiveExample("pages/js/map-prototype-clear.html")}}</div>



<h2 id="语法">语法</h2>

<pre class="syntaxbox"><code><em>myMap</em>.clear();</code>
</pre>

<h3 id="返回值">返回值</h3>

<p>{{jsxref("undefined")}}.</p>

<h2 id="示例">示例</h2>

<h3 id="调用clear方法">调用<code>clear</code>方法</h3>

<pre class="brush: js">var myMap = new Map();
myMap.set("bar", "baz");
myMap.set(1, "foo");

myMap.size;       // 2
myMap.has("bar"); // true

myMap.clear();

myMap.size;       // 0
myMap.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('ES2015', '#sec-map.prototype.clear', 'Map.prototype.clear')}}</td>
   <td>{{Spec2('ES2015')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-map.prototype.clear', 'Map.prototype.clear')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容">浏览器兼容</h2>



<p>{{Compat("javascript.builtins.Map.clear")}}</p>

<h2 id="相关链接">相关链接</h2>

<ul>
 <li>{{jsxref("Map")}}</li>
</ul>