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authorPeter Bengtsson <mail@peterbe.com>2020-12-08 14:40:17 -0500
committerPeter Bengtsson <mail@peterbe.com>2020-12-08 14:40:17 -0500
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+---
+title: Reflect.getOwnPropertyDescriptor()
+slug: Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor
+translation_of: Web/JavaScript/Reference/Global_Objects/Reflect/getOwnPropertyDescriptor
+---
+<div>{{JSRef}}</div>
+
+<p>静态方法 <code><strong>Reflect</strong></code><strong><code>.getOwnPropertyDescriptor()</code></strong> 与 {{jsxref("Object.getOwnPropertyDescriptor()")}} 方法相似。如果在对象中存在,则返回给定的属性的属性描述符。否则返回 {{jsxref("undefined")}}。 </p>
+
+<h2 id="语法">语法</h2>
+
+<pre class="syntaxbox">Reflect.getOwnPropertyDescriptor(target, propertyKey)
+</pre>
+
+<h3 id="参数">参数</h3>
+
+<dl>
+ <dt><code>target</code></dt>
+ <dd>需要寻找属性的目标对象。</dd>
+ <dt><code>propertyKey</code></dt>
+ <dd>获取自己的属性描述符的属性的名称。</dd>
+</dl>
+
+<h3 id="返回值">返回值</h3>
+
+<p>如果属性存在于给定的目标对象中,则返回属性描述符;否则,返回 {{jsxref("undefined")}}。</p>
+
+<h3 id="异常">异常</h3>
+
+<p>抛出一个 {{jsxref("TypeError")}},如果目标不是 {{jsxref("Object")}}。</p>
+
+<h2 id="描述">描述</h2>
+
+<p><code>Reflect.getOwnPropertyDescriptor</code>方法返回一个属性描述符,如果给定的属性存在于对象中,否则返回 {{jsxref("undefined")}} 。 与  {{jsxref("Object.getOwnPropertyDescriptor()")}} 的唯一不同在于如何处理非对象目标。</p>
+
+<h2 id="示例">示例</h2>
+
+<h3 id="使用_Reflect.getOwnPropertyDescriptor()">使用 <code>Reflect.getOwnPropertyDescriptor()</code></h3>
+
+<pre class="brush: js">Reflect.getOwnPropertyDescriptor({x: "hello"}, "x");
+// {value: "hello", writable: true, enumerable: true, configurable: true}
+
+Reflect.getOwnPropertyDescriptor({x: "hello"}, "y");
+// undefined
+
+Reflect.getOwnPropertyDescriptor([], "length");
+// {value: 0, writable: true, enumerable: false, configurable: false}
+</pre>
+
+<h3 id="与_Object.getOwnPropertyDescriptor()_的不同点">与 <code>Object.getOwnPropertyDescriptor() 的不同点</code></h3>
+
+<p>如果该方法的第一个参数不是一个对象(一个原始值),那么将造成 {{jsxref("TypeError")}} 错误。而对于 {{jsxref("Object.getOwnPropertyDescriptor")}},非对象的第一个参数将被强制转换为一个对象处理。</p>
+
+<pre class="brush: js">Reflect.getOwnPropertyDescriptor("foo", 0);
+// TypeError: "foo" is not non-null object
+
+Object.getOwnPropertyDescriptor("foo", 0);
+// { value: "f", writable: false, enumerable: true, configurable: 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('ES6', '#sec-reflect.getownpropertydescriptor', 'Reflect.getOwnPropertyDescriptor')}}</td>
+ <td>{{Spec2('ES6')}}</td>
+ <td>Initial definition.</td>
+ </tr>
+ <tr>
+ <td>{{SpecName('ESDraft', '#sec-reflect.getownpropertydescriptor', 'Reflect.getOwnPropertyDescriptor')}}</td>
+ <td>{{Spec2('ESDraft')}}</td>
+ <td> </td>
+ </tr>
+ </tbody>
+</table>
+
+<h2 id="浏览器兼容性">浏览器兼容性</h2>
+
+<p>{{CompatibilityTable}}</p>
+
+<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>49</td>
+ <td>{{CompatGeckoDesktop(42)}}</td>
+ <td>{{CompatNo}}</td>
+ <td>{{CompatNo}}</td>
+ <td>10</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>49</td>
+ <td>{{CompatGeckoMobile(42)}}</td>
+ <td>{{CompatNo}}</td>
+ <td>{{CompatNo}}</td>
+ <td>10</td>
+ </tr>
+ </tbody>
+</table>
+</div>
+
+<h2 id="相关链接">相关链接</h2>
+
+<ul>
+ <li>{{jsxref("Reflect")}}</li>
+ <li>{{jsxref("Object.getOwnPropertyDescriptor()")}}</li>
+</ul>