2019-04-21 11:50:48 +08:00

98 lines
4.1 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<article id="wikiArticle">
<div></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 <a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a> 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><code class="language-javascript"><code>Number.parseFloat(<var>string</var>)</code></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 <a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a> 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><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-number.parsefloat" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Number.parseFloat</small></a></p>
</td>
<td><span class="spec-Standard">Standard</span></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><div class="blockIndicator warning"><strong><a class="external" href="https://github.com/mdn/browser-compat-data" rel="noopener">We're converting our compatibility data into a machine-readable JSON format</a></strong>.
This compatibility table still uses the old format,
because we haven't yet converted the data it contains.
<strong><a class="new" href="/zh-CN/docs/MDN/Contribute/Structures/Compatibility_tables" rel="nofollow">Find out how you can help!</a></strong></div>
<div class="htab">
<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
<ul>
<li class="selected"><a>Desktop</a></li>
<li><a>Mobile</a></li>
</ul>
</div></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><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><a href="/en-US/Firefox/Releases/25" title="Released on 2013-10-29.">25</a> (25)</td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #f00;">未实现</span></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><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
<td>25.0 (25)</td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
</tr>
</tbody>
</table>
</div>
<h2 id="See_also" name="See_also">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/Number" title="JavaScript 的 Number 对象是经过封装的能让你处理数字值的对象。Number 对象由 Number() 构造器创建。"><code>Number</code></a></li>
<li><a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a></li>
</ul>
</article>