---
title: Number.parseFloat()
slug: Web/JavaScript/Reference/Global_Objects/Number/parseFloat
translation_of: Web/JavaScript/Reference/Global_Objects/Number/parseFloat
---
<div>{{JSRef("Global_Objects", "Number")}}</div>

<h2 id="Summary" name="Summary">概述</h2>

<p><strong><code>Number.parseFloat()</code></strong> 方法可以把一个字符串解析成浮点数。该方法与全局的 {{jsxref("Global_Objects/parseFloat", "parseFloat()")}} 函数相同，并且处于 ECMAScript 6 规范中（用于全局变量的模块化）。</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre class="syntaxbox"><code>Number.parseFloat(<var>string</var>)</code></pre>

<h3 id="Parameters" name="Parameters">参数</h3>

<dl>
 <dt><code>string</code></dt>
 <dd>被解析的字符串。</dd>
</dl>

<h3 id="返回值">返回值</h3>

<dl>
 <dd>给定值被解析成浮点数，如果无法被解析成浮点数，则返回<code>NaN</code></dd>
</dl>

<h2 id="描述">描述</h2>

<p>请移步全局函数 {{jsxref("Global_Objects/parseFloat", "parseFloat()")}} 页面查看更多的解释和示例。</p>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">规范版本</th>
   <th scope="col">规范状态</th>
   <th scope="col">注解</th>
  </tr>
  <tr>
   <td>
    <p>{{SpecName('ES6', '#sec-number.parsefloat', 'Number.parseFloat')}}</p>
   </td>
   <td>{{Spec2('ES6')}}</td>
   <td>首次定义</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>

<div>{{CompatibilityTable}}</div>

<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>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop("25")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatVersionUnknown}}</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("25")}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_also" name="See_also">相关链接</h2>

<ul>
 <li>{{jsxref("Global_Objects/Number", "Number")}}</li>
 <li>{{jsxref("Global_Objects/parseFloat", "parseFloat()")}}</li>
</ul>