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---
title: Map.prototype.clear()
slug: Web/JavaScript/Reference/Global_Objects/Map/clear
translation_of: Web/JavaScript/Reference/Global_Objects/Map/clear
tags:
- ECMAScript 2015
- JavaScript
- Map
- Method
- Prototype
- Reference
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>
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