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author | Florian Merz <me@fiji-flo.de> | 2021-02-11 12:56:40 +0100 |
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committer | Florian Merz <me@fiji-flo.de> | 2021-02-11 12:56:40 +0100 |
commit | 310fd066e91f454b990372ffa30e803cc8120975 (patch) | |
tree | d5d900deb656a5da18e0b60d00f0db73f3a2e88e /files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get | |
parent | 8260a606c143e6b55a467edf017a56bdcd6cba7e (diff) | |
download | translated-content-310fd066e91f454b990372ffa30e803cc8120975.tar.gz translated-content-310fd066e91f454b990372ffa30e803cc8120975.tar.bz2 translated-content-310fd066e91f454b990372ffa30e803cc8120975.zip |
unslug zh-cn: move
Diffstat (limited to 'files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get')
-rw-r--r-- | files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get/index.html | 177 |
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diff --git a/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get/index.html b/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get/index.html deleted file mode 100644 index 14a350436a..0000000000 --- a/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/get/index.html +++ /dev/null @@ -1,177 +0,0 @@ ---- -title: handler.get() -slug: Web/JavaScript/Reference/Global_Objects/Proxy/handler/get -tags: - - ECMAScript6 - - JavaScript - - Method - - Proxy -translation_of: Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/get ---- -<div>{{JSRef}}</div> - -<p><strong><code>handler.get()</code></strong> 方法用于拦截对象的读取属性操作。</p> - -<h2 id="语法">语法</h2> - -<pre class="brush: js">var p = new Proxy(target, { - get: function(target, property, receiver) { - } -}); -</pre> - -<h3 id="参数">参数</h3> - -<p>以下是传递给get方法的参数,<code>this上下文绑定在</code>handler对象上.</p> - -<dl> - <dt><code>target</code></dt> - <dd>目标对象。</dd> - <dt><code>property</code></dt> - <dd>被获取的属性名。</dd> - <dt><code>receiver</code></dt> - <dd>Proxy或者继承Proxy的对象</dd> -</dl> - -<h3 id="返回值">返回值</h3> - -<p>get方法可以返回任何值。</p> - -<h2 id="描述">描述</h2> - -<p><strong><code>handler.get</code></strong> 方法用于拦截对象的读取属性操作。</p> - -<h3 id="拦截">拦截</h3> - -<p>该方法会拦截目标对象的以下操作:</p> - -<ul> - <li>访问属性: <code>proxy[foo]和</code> <code>proxy.bar</code></li> - <li>访问原型链上的属性: <code>Object.create(proxy)[foo]</code></li> - <li>{{jsxref("Reflect.get()")}}</li> -</ul> - -<h3 id="约束">约束</h3> - -<p>如果违背了以下的约束,proxy会抛出 {{jsxref("TypeError")}}:</p> - -<ul> - <li>如果要访问的目标属性是不可写以及不可配置的,则返回的值必须与该目标属性的值相同。</li> - <li>如果要访问的目标属性没有配置访问方法,即get方法是undefined的,则返回值必须为undefined。</li> -</ul> - -<h2 id="示例">示例</h2> - -<p>以下代码演示如何拦截属性值的读取操作。</p> - -<pre class="brush: js">var p = new Proxy({}, { - get: function(target, prop, receiver) { - console.log("called: " + prop); - return 10; - } -}); - -console.log(p.a); // "called: a" - // 10 -</pre> - -<p>以下代码演示违反约束的情况。</p> - -<pre class="brush: js">var obj = {}; -Object.defineProperty(obj, "a", { - configurable: false, - enumerable: false, - value: 10, - writable: false -}); - -var p = new Proxy(obj, { - get: function(target, prop) { - return 20; - } -}); - -p.a; //会抛出TypeError -</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-proxy-object-internal-methods-and-internal-slots-get-p-receiver', '[[Get]]')}}</td> - <td>{{Spec2('ES2015')}}</td> - <td>Initial definition.</td> - </tr> - <tr> - <td>{{SpecName('ESDraft', '#sec-proxy-object-internal-methods-and-internal-slots-get-p-receiver', '[[Get]]')}}</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> - -<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>{{CompatUnknown}}</td> - <td>{{CompatGeckoDesktop("18")}}</td> - <td>{{CompatUnknown}}</td> - <td>{{CompatUnknown}}</td> - <td>{{CompatUnknown}}</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>{{CompatUnknown}}</td> - <td>{{CompatUnknown}}</td> - <td>{{CompatGeckoMobile("18")}}</td> - <td>{{CompatUnknown}}</td> - <td>{{CompatUnknown}}</td> - <td>{{CompatUnknown}}</td> - </tr> - </tbody> -</table> -</div> - -<h2 id="另见">另见</h2> - -<ul> - <li>{{jsxref("Proxy")}}</li> - <li>{{jsxref("Proxy.handler", "handler")}}</li> - <li>{{jsxref("Reflect.get()")}}</li> -</ul> |