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Diffstat (limited to 'files/zh-cn/web/javascript/reference/global_objects/number/valueof')
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diff --git a/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html b/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html new file mode 100644 index 0000000000..81168e6ea0 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/number/valueof/index.html @@ -0,0 +1,122 @@ +--- +title: Number.prototype.valueOf() +slug: Web/JavaScript/Reference/Global_Objects/Number/valueOf +tags: + - JavaScript + - Method + - Number + - valueOf() +translation_of: Web/JavaScript/Reference/Global_Objects/Number/valueOf +--- +<div>{{JSRef("Global_Objects", "Number")}}</div> + +<h2 id="Summary" name="Summary">概述</h2> + +<p><strong><code>valueOf()</code></strong> 方法返回一个被 {{jsxref("Global_Objects/Number", "Number")}} 对象包装的原始值。</p> + +<h2 id="Syntax" name="Syntax">语法</h2> + +<pre class="syntaxbox"><code><var>numObj</var>.valueOf()</code></pre> + +<h3 id="Parameters" name="Parameters">返回值</h3> + +<p>表示指定 {{jsxref("Number")}} 对象的原始值的数字</p> + +<h2 id="Description" name="Description">描述</h2> + +<p>该方法通常是由 JavaScript 引擎在内部隐式调用的,而不是由用户在代码中显式调用的。</p> + +<h2 id="Examples" name="Examples">示例</h2> + +<pre class="brush: js">var numObj = new Number(10); +console.log(typeof numObj); // object + +var num = numObj.valueOf(); +console.log(num); // 10 +console.log(typeof num); // number +</pre> + +<h2 id="规范">规范</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">规范名称</th> + <th scope="col">规范状态</th> + <th scope="col">备注</th> + </tr> + <tr> + <td>ECMAScript 1st Edition.</td> + <td>Standard</td> + <td> </td> + </tr> + <tr> + <td>{{SpecName('ES5.1', '#sec-15.7.4.4', 'Number.prototype.valueOf')}}</td> + <td>{{Spec2('ES5.1')}}</td> + <td> </td> + </tr> + <tr> + <td>{{SpecName('ES6', '#sec-number.prototype.valueof', 'Number.prototype.valueOf')}}</td> + <td>{{Spec2('ES6')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="浏览器兼容性">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>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</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>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<h2 id="See_also" name="See_also">相关链接</h2> + +<ul> + <li>{{jsxref("Number.prototype.toSource()")}}</li> +</ul> |