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diff --git a/files/zh-tw/web/javascript/reference/global_objects/object/defineproperties/index.html b/files/zh-tw/web/javascript/reference/global_objects/object/defineproperties/index.html new file mode 100644 index 0000000000..fc87ca0317 --- /dev/null +++ b/files/zh-tw/web/javascript/reference/global_objects/object/defineproperties/index.html @@ -0,0 +1,224 @@ +--- +title: Object.defineProperties() +slug: Web/JavaScript/Reference/Global_Objects/Object/defineProperties +translation_of: Web/JavaScript/Reference/Global_Objects/Object/defineProperties +--- +<div>{{JSRef}}</div> + +<p><code><strong>Object.defineProperties()</strong></code> 函式可定義新的或是修改已存在的物件屬性，並回傳修改後的物件。</p> + +<h2 id="語法">語法</h2> + +<pre class="syntaxbox"><code>Object.defineProperties(<var>obj</var>, <var>props</var>)</code></pre> + +<h3 id="參數">參數</h3> + +<dl> + <dt><code>obj</code></dt> + <dd>The object on which to define or modify properties.</dd> + <dt><code>props</code></dt> + <dd>An object whose own enumerable properties constitute descriptors for the properties to be defined or modified. Property descriptors present in objects come in two main flavors: data descriptors and accessor descriptors (see {{jsxref("Object.defineProperty()")}} for more details). Descriptors have the following keys:</dd> + <dd> + <dl> + <dt><code>configurable</code></dt> + <dd><code>true</code> if and only if the type of this property descriptor may be changed and if the property may be deleted from the corresponding object.<br> + <strong>預設為 <code>false</code>.</strong></dd> + <dt><code>enumerable</code></dt> + <dd><code>若該屬性設為 true，則該屬性可被物件所列舉。</code><br> + <strong>預設為 <code>false</code>.</strong></dd> + </dl> + + <dl> + <dt><code>value</code></dt> + <dd>The value associated with the property. Can be any valid JavaScript value (number, object, function, etc).<br> + <strong>預設為 {{jsxref("undefined")}}.</strong></dd> + <dt><code>writable</code></dt> + <dd><code>若該屬性為 true</code>，則該屬性可透過{{jsxref("Operators/Assignment_Operators", "賦予運算子", "", 1)}}所改變<br> + <strong>預設為 <code>false</code>.</strong></dd> + </dl> + + <dl> + <dt><code>get</code></dt> + <dd>A function which serves as a getter for the property, or {{jsxref("undefined")}} if there is no getter. The function return will be used as the value of property.<br> + <strong>預設為 {{jsxref("undefined")}}.</strong></dd> + <dt><code>set</code></dt> + <dd>A function which serves as a setter for the property, or {{jsxref("undefined")}} if there is no setter. The function will receive as only argument the new value being assigned to the property.<br> + <strong>預設為 {{jsxref("undefined")}}.</strong></dd> + </dl> + </dd> +</dl> + +<h3 id="回傳值">回傳值</h3> + +<p>The object that was passed to the function.</p> + +<h2 id="描述">描述</h2> + +<p><code>Object.defineProperties</code>, in essence, defines all properties corresponding to the enumerable own properties of <code>props</code> on the object <code>obj</code> object.</p> + +<h2 id="範例">範例</h2> + +<pre class="brush: js">var obj = {}; +Object.defineProperties(obj, { + 'property1': { + value: true, + writable: true + }, + 'property2': { + value: 'Hello', + writable: false + } + // etc. etc. +}); +</pre> + +<h2 id="Polyfill">Polyfill</h2> + +<p>Assuming a pristine execution environment with all names and properties referring to their initial values, <code>Object.defineProperties</code> is almost completely equivalent (note the comment in <code>isCallable</code>) to the following reimplementation in JavaScript:</p> + +<pre class="brush: js;highlight:[8]">function defineProperties(obj, properties) { + function convertToDescriptor(desc) { + function hasProperty(obj, prop) { + return Object.prototype.hasOwnProperty.call(obj, prop); + } + + function isCallable(v) { + // NB: modify as necessary if other values than functions are callable. + return typeof v === 'function'; + } + + if (typeof desc !== 'object' || desc === null) + throw new TypeError('bad desc'); + + var d = {}; + + if (hasProperty(desc, 'enumerable')) + d.enumerable = !!desc.enumerable; + if (hasProperty(desc, 'configurable')) + d.configurable = !!desc.configurable; + if (hasProperty(desc, 'value')) + d.value = desc.value; + if (hasProperty(desc, 'writable')) + d.writable = !!desc.writable; + if (hasProperty(desc, 'get')) { + var g = desc.get; + + if (!isCallable(g) && typeof g !== 'undefined') + throw new TypeError('bad get'); + d.get = g; + } + if (hasProperty(desc, 'set')) { + var s = desc.set; + if (!isCallable(s) && typeof s !== 'undefined') + throw new TypeError('bad set'); + d.set = s; + } + + if (('get' in d || 'set' in d) && ('value' in d || 'writable' in d)) + throw new TypeError('identity-confused descriptor'); + + return d; + } + + if (typeof obj !== 'object' || obj === null) + throw new TypeError('bad obj'); + + properties = Object(properties); + + var keys = Object.keys(properties); + var descs = []; + + for (var i = 0; i < keys.length; i++) + descs.push([keys[i], convertToDescriptor(properties[keys[i]])]); + + for (var i = 0; i < descs.length; i++) + Object.defineProperty(obj, descs[i][0], descs[i][1]); + + return obj; +} +</pre> + +<h2 id="規格">規格</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">註記</th> + </tr> + <tr> + <td>{{SpecName('ES5.1', '#sec-15.2.3.7', 'Object.defineProperties')}}</td> + <td>{{Spec2('ES5.1')}}</td> + <td>Initial definition. Implemented in JavaScript 1.8.5</td> + </tr> + <tr> + <td>{{SpecName('ES6', '#sec-object.defineproperties', 'Object.defineProperties')}}</td> + <td>{{Spec2('ES6')}}</td> + <td> </td> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-object.defineproperties', 'Object.defineProperties')}}</td> + <td>{{Spec2('ESDraft')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="瀏覽器相容性">瀏覽器相容性</h2> + +<div>{{CompatibilityTable}}</div> + +<div id="compat-desktop"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Firefox (Gecko)</th> + <th>Chrome</th> + <th>Internet Explorer</th> + <th>Opera</th> + <th>Safari</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatGeckoDesktop("2")}}</td> + <td>{{CompatChrome("5")}}</td> + <td>{{CompatIE("9")}}</td> + <td>{{CompatOpera("11.60")}}</td> + <td>{{CompatSafari("5")}}</td> + </tr> + </tbody> +</table> +</div> + +<div id="compat-mobile"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Firefox Mobile (Gecko)</th> + <th>Android</th> + <th>IE Mobile</th> + <th>Opera Mobile</th> + <th>Safari Mobile</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatGeckoMobile("2")}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatUnknown}}</td> + <td>{{CompatOperaMobile("11.5")}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<h2 id="參閱">參閱</h2> + +<ul> + <li>{{jsxref("Object.defineProperty()")}}</li> + <li>{{jsxref("Object.keys()")}}</li> + <li><a href="/en-US/docs/Enumerability_and_ownership_of_properties">Enumerability and ownership of properties</a></li> +</ul> |