{"id":632,"date":"2024-06-02T22:02:37","date_gmt":"2024-06-02T14:02:37","guid":{"rendered":"https:\/\/levin.ink\/?p=632"},"modified":"2024-06-17T23:33:41","modified_gmt":"2024-06-17T15:33:41","slug":"js-3-6-%e5%af%b9%e8%b1%a1%e5%b1%9e%e6%80%a7%e9%85%8d%e7%bd%ae","status":"publish","type":"post","link":"https:\/\/levin.ink\/?p=632","title":{"rendered":"JS &#8211; 3-6 \u5bf9\u8c61\u5c5e\u6027\u914d\u7f6e"},"content":{"rendered":"<h1>\u5c5e\u6027\u6807\u5fd7\u548c\u5c5e\u6027\u63cf\u8ff0\u7b26<\/h1>\n<p>\u6211\u4eec\u77e5\u9053\uff0c\u5bf9\u8c61\u53ef\u4ee5\u5b58\u50a8\u5c5e\u6027\u3002<br \/>\n\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u5c5e\u6027\u5bf9\u6211\u4eec\u6765\u8bf4\u53ea\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u201c\u952e\u503c\u201d\u5bf9\u3002\u4f46\u5bf9\u8c61\u5c5e\u6027\u5b9e\u9645\u4e0a\u662f\u66f4\u7075\u6d3b\u4e14\u66f4\u5f3a\u5927\u7684\u4e1c\u897f\u3002<\/p>\n<h2>\u5c5e\u6027\u6807\u5fd7<\/h2>\n<p>\u5bf9\u8c61\u5c5e\u6027\uff08properties\uff09\uff0c\u9664\u00a0<strong><code>value<\/code><\/strong>\u00a0\u5916\uff0c\u8fd8\u6709\u4e09\u4e2a\u7279\u6b8a\u7684\u7279\u6027\uff08attributes\uff09\uff0c\u4e5f\u5c31\u662f\u6240\u8c13\u7684\u201c\u6807\u5fd7\u201d\uff1a<\/p>\n<ul>\n<li><strong><code>writable<\/code><\/strong>\u00a0\u2014 \u5982\u679c\u4e3a\u00a0<code>true<\/code>\uff0c\u5219\u503c\u53ef\u4ee5\u88ab\u4fee\u6539\uff0c\u5426\u5219\u5b83\u662f\u53ea\u53ef\u8bfb\u7684\u3002<\/li>\n<li><strong><code>enumerable<\/code><\/strong>\u00a0\u2014 \u5982\u679c\u4e3a\u00a0<code>true<\/code>\uff0c\u5219\u4f1a\u88ab\u5728\u5faa\u73af\u4e2d\u5217\u51fa\uff0c\u5426\u5219\u4e0d\u4f1a\u88ab\u5217\u51fa\u3002<\/li>\n<li><strong><code>configurable<\/code><\/strong>\u00a0\u2014 \u5982\u679c\u4e3a\u00a0<code>true<\/code>\uff0c\u5219\u6b64\u5c5e\u6027\u53ef\u4ee5\u88ab\u5220\u9664\uff0c\u8fd9\u4e9b\u7279\u6027\u4e5f\u53ef\u4ee5\u88ab\u4fee\u6539\uff0c\u5426\u5219\u4e0d\u53ef\u4ee5\u3002<br \/>\n\u6211\u4eec\u5230\u73b0\u5728\u8fd8\u6ca1\u770b\u5230\u5b83\u4eec\uff0c\u662f\u56e0\u4e3a\u5b83\u4eec\u901a\u5e38\u4e0d\u4f1a\u51fa\u73b0\u3002\u5f53\u6211\u4eec\u7528\u201c\u5e38\u7528\u7684\u65b9\u5f0f\u201d\u521b\u5efa\u4e00\u4e2a\u5c5e\u6027\u65f6\uff0c\u5b83\u4eec\u90fd\u4e3a\u00a0<code>true<\/code>\u3002\u4f46\u6211\u4eec\u4e5f\u53ef\u4ee5\u968f\u65f6\u66f4\u6539\u5b83\u4eec\u3002<br \/>\n\u9996\u5148\uff0c\u8ba9\u6211\u4eec\u6765\u770b\u770b\u5982\u4f55\u83b7\u5f97\u8fd9\u4e9b\u6807\u5fd7\u3002<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/getOwnPropertyDescriptor\">Object.getOwnPropertyDescriptor<\/a>\u00a0\u65b9\u6cd5\u5141\u8bb8\u67e5\u8be2\u6709\u5173\u5c5e\u6027\u7684\u00a0<strong>\u5b8c\u6574<\/strong>\u00a0\u4fe1\u606f\u3002<br \/>\n\u8bed\u6cd5\u662f\uff1a<\/li>\n<\/ul>\n<pre><code class=\"language-js\">let descriptor = Object.getOwnPropertyDescriptor(obj, propertyName);\n<\/code><\/pre>\n<p><code>obj<\/code><br \/>\n\u9700\u8981\u4ece\u4e2d\u83b7\u53d6\u4fe1\u606f\u7684\u5bf9\u8c61\u3002<br \/>\n<code>propertyName<\/code><br \/>\n\u5c5e\u6027\u7684\u540d\u79f0\u3002<br \/>\n\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u6240\u8c13\u7684\u201c\u5c5e\u6027\u63cf\u8ff0\u7b26\u201d\u5bf9\u8c61\uff1a\u5b83\u5305\u542b\u503c\u548c\u6240\u6709\u7684\u6807\u5fd7\u3002<\/p>\n<pre><code class=\"language-js\">let user = {\n  name: &quot;John&quot;\n};\n\nlet descriptor = Object.getOwnPropertyDescriptor(user, 'name');\n\nalert( JSON.stringify(descriptor, null, 2 ) );\n\/* \u5c5e\u6027\u63cf\u8ff0\u7b26\uff1a\n{\n  &quot;value&quot;: &quot;John&quot;,\n  &quot;writable&quot;: true,\n  &quot;enumerable&quot;: true,\n  &quot;configurable&quot;: true\n}\n*\/\n<\/code><\/pre>\n<p>\u4e3a\u4e86\u4fee\u6539\u6807\u5fd7\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/defineProperty\">Object.defineProperty<\/a>\u3002<br \/>\n\u8bed\u6cd5\u662f\uff1a<\/p>\n<pre><code class=\"language-js\">Object.defineProperty(obj, propertyName, descriptor)\n<\/code><\/pre>\n<p><code>obj<\/code>\uff0c<code>propertyName<\/code><br \/>\n\u8981\u5e94\u7528\u63cf\u8ff0\u7b26\u7684\u5bf9\u8c61\u53ca\u5176\u5c5e\u6027\u3002<br \/>\n<code>descriptor<\/code><br \/>\n\u8981\u5e94\u7528\u7684\u5c5e\u6027\u63cf\u8ff0\u7b26\u5bf9\u8c61\u3002<br \/>\n\u5982\u679c\u8be5\u5c5e\u6027\u5b58\u5728\uff0c<code>defineProperty<\/code>\u00a0\u4f1a\u66f4\u65b0\u5176\u6807\u5fd7\u3002\u5426\u5219\uff0c\u5b83\u4f1a\u4f7f\u7528\u7ed9\u5b9a\u7684\u503c\u548c\u6807\u5fd7\u521b\u5efa\u5c5e\u6027\uff1b\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u6ca1\u6709\u63d0\u4f9b\u6807\u5fd7\uff0c\u5219\u4f1a\u5047\u5b9a\u5b83\u662f\u00a0<code>false<\/code>\u3002<\/p>\n<pre><code class=\"language-js\">let user = {};\n\nObject.defineProperty(user, &quot;name&quot;, {\n  value: &quot;John&quot;\n});\n\nlet descriptor = Object.getOwnPropertyDescriptor(user, 'name');\n\nalert( JSON.stringify(descriptor, null, 2 ) );\n\/*\n{\n  &quot;value&quot;: &quot;John&quot;,\n  &quot;writable&quot;: false,\n  &quot;enumerable&quot;: false,\n  &quot;configurable&quot;: false\n}\n *\/\n<\/code><\/pre>\n<p>\u5c06\u5b83\u4e0e\u4e0a\u9762\u7684\u201c\u4ee5\u5e38\u7528\u65b9\u5f0f\u521b\u5efa\u7684\u201d\u00a0<code>user.name<\/code>\u00a0\u8fdb\u884c\u6bd4\u8f83\uff1a\u73b0\u5728\u6240\u6709\u6807\u5fd7\u90fd\u4e3a\u00a0<code>false<\/code>\u3002\u5982\u679c\u8fd9\u4e0d\u662f\u6211\u4eec\u60f3\u8981\u7684\uff0c\u90a3\u4e48\u6211\u4eec\u6700\u597d\u5728\u00a0<code>descriptor<\/code>\u00a0\u4e2d\u5c06\u5b83\u4eec\u8bbe\u7f6e\u4e3a\u00a0<code>true<\/code>\u3002<\/p>\n<h2>\u53ea\u8bfb<\/h2>\n<p>\u901a\u8fc7\u66f4\u6539\u00a0<code>writable<\/code>\u00a0\u6807\u5fd7\u6765\u628a\u00a0<code>user.name<\/code>\u00a0\u8bbe\u7f6e\u4e3a\u53ea\u8bfb\uff08<code>user.name<\/code>\u00a0\u4e0d\u80fd\u88ab\u91cd\u65b0\u8d4b\u503c\uff09<br \/>\n\u73b0\u5728\u6ca1\u6709\u4eba\u53ef\u4ee5\u6539\u53d8\u6211\u4eec\u00a0<code>user<\/code>\u00a0\u7684\u00a0<code>name<\/code>\uff0c\u9664\u975e\u5b83\u4eec\u5e94\u7528\u81ea\u5df1\u7684\u00a0<code>defineProperty<\/code>\u00a0\u6765\u8986\u76d6\u6211\u4eec\u7684\u00a0<code>user<\/code>\u00a0\u7684\u00a0<code>name<\/code>\u3002<\/p>\n<blockquote>\n<p>\u53ea\u5728\u4e25\u683c\u6a21\u5f0f\u4e0b\u4f1a\u51fa\u73b0 Errors<br \/>\n\u5728\u975e\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5728\u5bf9\u4e0d\u53ef\u5199\u7684\u5c5e\u6027\u7b49\u8fdb\u884c\u5199\u5165\u64cd\u4f5c\u65f6\uff0c\u4e0d\u4f1a\u51fa\u73b0\u9519\u8bef\u3002\u4f46\u662f\u64cd\u4f5c\u4ecd\u7136\u4e0d\u4f1a\u6210\u529f\u3002\u5728\u975e\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u8fdd\u53cd\u6807\u5fd7\u7684\u884c\u4e3a\uff08flag-violating action\uff09\u53ea\u4f1a\u88ab\u9ed8\u9ed8\u5730\u5ffd\u7565\u6389\u3002<\/p>\n<\/blockquote>\n<h2>\u4e0d\u53ef\u679a\u4e3e<\/h2>\n<p>\u73b0\u5728\u8ba9\u6211\u4eec\u5411\u00a0<code>user<\/code>\u00a0\u6dfb\u52a0\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684\u00a0<code>toString<\/code>\u3002<br \/>\n\u901a\u5e38\uff0c\u5bf9\u8c61\u4e2d\u5185\u5efa\u7684\u00a0<code>toString<\/code>\u00a0\u662f\u4e0d\u53ef\u679a\u4e3e\u7684\uff0c\u5b83\u4e0d\u4f1a\u663e\u793a\u5728\u00a0<code>for..in<\/code>\u00a0\u4e2d\u3002\u4f46\u662f\u5982\u679c\u6211\u4eec\u6dfb\u52a0\u6211\u4eec\u81ea\u5df1\u7684\u00a0<code>toString<\/code>\uff0c\u90a3\u4e48\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u5b83\u5c06\u663e\u793a\u5728\u00a0<code>for..in<\/code>\u00a0\u4e2d<br \/>\n\u5982\u679c\u6211\u4eec\u4e0d\u559c\u6b22\u5b83\uff0c\u90a3\u4e48\u6211\u4eec\u53ef\u4ee5\u8bbe\u7f6e\u00a0<code>enumerable:false<\/code>\u3002\u4e4b\u540e\u5b83\u5c31\u4e0d\u4f1a\u51fa\u73b0\u5728\u00a0<code>for..in<\/code>\u00a0\u5faa\u73af\u4e2d\u4e86\uff0c\u5c31\u50cf\u5185\u5efa\u7684\u00a0<code>toString<\/code>\u00a0\u4e00\u6837<br \/>\n\u4e0d\u53ef\u679a\u4e3e\u7684\u5c5e\u6027\u4e5f\u4f1a\u88ab\u00a0<code>Object.keys<\/code>\u00a0\u6392\u9664<\/p>\n<h2>\u4e0d\u53ef\u914d\u7f6e<\/h2>\n<p>\u4e0d\u53ef\u914d\u7f6e\u6807\u5fd7\uff08<code>configurable:false<\/code>\uff09\u6709\u65f6\u4f1a\u9884\u8bbe\u5728\u5185\u5efa\u5bf9\u8c61\u548c\u5c5e\u6027\u4e2d\u3002<br \/>\n\u4e0d\u53ef\u914d\u7f6e\u7684\u5c5e\u6027\u4e0d\u80fd\u88ab\u5220\u9664\uff0c\u5b83\u7684\u7279\u6027\uff08attribute\uff09\u4e0d\u80fd\u88ab\u4fee\u6539\u3002<br \/>\n\u4f8b\u5982\uff0c<code>Math.PI<\/code>\u00a0\u662f\u53ea\u8bfb\u7684\u3001\u4e0d\u53ef\u679a\u4e3e\u548c\u4e0d\u53ef\u914d\u7f6e\u7684<br \/>\n\u56e0\u6b64\uff0c\u5f00\u53d1\u4eba\u5458\u65e0\u6cd5\u4fee\u6539\u00a0<code>Math.PI<\/code>\u00a0\u7684\u503c\u6216\u8986\u76d6\u5b83\u3002\u6211\u4eec\u4e5f\u65e0\u6cd5\u5c06\u00a0<code>Math.PI<\/code>\u00a0\u6539\u4e3a\u00a0<code>writable<\/code><br \/>\n\u6211\u4eec\u5bf9\u00a0<code>Math.PI<\/code>\u00a0\u4ec0\u4e48\u4e5f\u505a\u4e0d\u4e86\u3002<br \/>\n\u4f7f\u5c5e\u6027\u53d8\u6210\u4e0d\u53ef\u914d\u7f6e\u662f\u4e00\u6761\u5355\u884c\u9053\u3002\u6211\u4eec\u65e0\u6cd5\u901a\u8fc7\u00a0<code>defineProperty<\/code>\u00a0\u518d\u628a\u5b83\u6539\u56de\u6765\u3002<br \/>\n<strong>\u8bf7\u6ce8\u610f\uff1a<code>configurable: false<\/code>\u00a0\u9632\u6b62\u66f4\u6539\u548c\u5220\u9664\u5c5e\u6027\u6807\u5fd7\uff0c\u4f46\u662f\u5141\u8bb8\u66f4\u6539\u5bf9\u8c61\u7684\u503c\u3002<\/strong><br \/>\n\u8fd9\u91cc\u7684\u00a0<code>user.name<\/code>\u00a0\u662f\u4e0d\u53ef\u914d\u7f6e\u7684\uff0c\u4f46\u662f\u6211\u4eec\u4ecd\u7136\u53ef\u4ee5\u66f4\u6539\u5b83\uff0c\u56e0\u4e3a\u5b83\u662f\u53ef\u5199\u7684\uff1a<br \/>\n\u552f\u4e00\u53ef\u884c\u7684\u7279\u6027\u66f4\u6539\uff1awritable true \u2192 false<br \/>\n\u5bf9\u4e8e\u66f4\u6539\u6807\u5fd7\uff0c\u6709\u4e00\u4e2a\u5c0f\u4f8b\u5916\u3002<br \/>\n\u5bf9\u4e8e\u4e0d\u53ef\u914d\u7f6e\u7684\u5c5e\u6027\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u00a0<code>writable: true<\/code>\u00a0\u66f4\u6539\u4e3a\u00a0<code>false<\/code>\uff0c\u4ece\u800c\u9632\u6b62\u5176\u503c\u88ab\u4fee\u6539\uff08\u4ee5\u6dfb\u52a0\u53e6\u4e00\u5c42\u4fdd\u62a4\uff09\u3002\u4f46\u65e0\u6cd5\u53cd\u5411\u884c\u4e4b\u3002<\/p>\n<h2>Object.defineProperties<\/h2>\n<p>\u6709\u4e00\u4e2a\u65b9\u6cd5\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/defineProperties\">Object.defineProperties(obj, descriptors)<\/a>\uff0c\u5141\u8bb8\u4e00\u6b21\u5b9a\u4e49\u591a\u4e2a\u5c5e\u6027\u3002<\/p>\n<pre><code class=\"language-js\">Object.defineProperties(obj, {\n  prop1: descriptor1,\n  prop2: descriptor2\n  \/\/ ...\n});\n<\/code><\/pre>\n<pre><code class=\"language-js\">Object.defineProperties(user, {\n  name: { value: &quot;John&quot;, writable: false },\n  surname: { value: &quot;Smith&quot;, writable: false },\n  \/\/ ...\n});\n<\/code><\/pre>\n<h2>Object.getOwnPropertyDescriptors<\/h2>\n<p>\u8981\u4e00\u6b21\u83b7\u53d6\u6240\u6709\u5c5e\u6027\u63cf\u8ff0\u7b26\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/getOwnPropertyDescriptors\">Object.getOwnPropertyDescriptors(obj)<\/a>\u00a0\u65b9\u6cd5\u3002<br \/>\n\u5b83\u4e0e\u00a0<code>Object.defineProperties<\/code>\u00a0\u4e00\u8d77\u53ef\u4ee5\u7528\u4f5c\u514b\u9686\u5bf9\u8c61\u7684\u201c\u6807\u5fd7\u611f\u77e5\u201d\u65b9\u5f0f\uff1a<\/p>\n<pre><code class=\"language-js\">let clone = Object.defineProperties({}, Object.getOwnPropertyDescriptors(obj));s\n<\/code><\/pre>\n<p>\u901a\u5e38\uff0c\u5f53\u6211\u4eec\u514b\u9686\u4e00\u4e2a\u5bf9\u8c61\u65f6\uff0c\u6211\u4eec\u4f7f\u7528\u8d4b\u503c\u7684\u65b9\u5f0f\u6765\u590d\u5236\u5c5e\u6027<br \/>\n\u2026\u2026\u4f46\u662f\uff0c\u8fd9\u5e76\u4e0d\u80fd\u590d\u5236\u6807\u5fd7\u3002\u6240\u4ee5\u5982\u679c\u6211\u4eec\u60f3\u8981\u4e00\u4e2a\u201c\u66f4\u597d\u201d\u7684\u514b\u9686\uff0c\u90a3\u4e48\u00a0<code>Object.defineProperties<\/code>\u00a0\u662f\u9996\u9009\u3002<br \/>\n\u53e6\u4e00\u4e2a\u533a\u522b\u662f\u00a0<code>for..in<\/code>\u00a0\u4f1a\u5ffd\u7565 symbol \u7c7b\u578b\u7684\u548c\u4e0d\u53ef\u679a\u4e3e\u7684\u5c5e\u6027\uff0c\u4f46\u662f\u00a0<code>Object.getOwnPropertyDescriptors<\/code>\u00a0\u8fd4\u56de\u5305\u542b symbol \u7c7b\u578b\u7684\u548c\u4e0d\u53ef\u679a\u4e3e\u7684\u5c5e\u6027\u5728\u5185\u7684\u00a0<strong>\u6240\u6709<\/strong>\u00a0\u5c5e\u6027\u63cf\u8ff0\u7b26\u3002<\/p>\n<h2>\u8bbe\u5b9a\u4e00\u4e2a\u5168\u5c40\u7684\u5bc6\u5c01\u5bf9\u8c61<\/h2>\n<p>\u5c5e\u6027\u63cf\u8ff0\u7b26\u5728\u5355\u4e2a\u5c5e\u6027\u7684\u7ea7\u522b\u4e0a\u5de5\u4f5c\u3002<br \/>\n\u8fd8\u6709\u4e00\u4e9b\u9650\u5236\u8bbf\u95ee\u00a0<strong>\u6574\u4e2a<\/strong>\u00a0\u5bf9\u8c61\u7684\u65b9\u6cd5\uff1a<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/preventExtensions\">Object.preventExtensions(obj)<\/a><br \/>\n\u7981\u6b62\u5411\u5bf9\u8c61\u6dfb\u52a0\u65b0\u5c5e\u6027\u3002<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/seal\">Object.seal(obj)<\/a><br \/>\n\u7981\u6b62\u6dfb\u52a0\/\u5220\u9664\u5c5e\u6027\u3002\u4e3a\u6240\u6709\u73b0\u6709\u7684\u5c5e\u6027\u8bbe\u7f6e\u00a0<code>configurable: false<\/code>\u3002<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/freeze\">Object.freeze(obj)<\/a><br \/>\n\u7981\u6b62\u6dfb\u52a0\/\u5220\u9664\/\u66f4\u6539\u5c5e\u6027\u3002\u4e3a\u6240\u6709\u73b0\u6709\u7684\u5c5e\u6027\u8bbe\u7f6e\u00a0<code>configurable: false, writable: false<\/code>\u3002<br \/>\n\u8fd8\u6709\u9488\u5bf9\u5b83\u4eec\u7684\u6d4b\u8bd5\uff1a<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/isExtensible\">Object.isExtensible(obj)<\/a><br \/>\n\u5982\u679c\u6dfb\u52a0\u5c5e\u6027\u88ab\u7981\u6b62\uff0c\u5219\u8fd4\u56de\u00a0<code>false<\/code>\uff0c\u5426\u5219\u8fd4\u56de\u00a0<code>true<\/code>\u3002<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/isSealed\">Object.isSealed(obj)<\/a><br \/>\n\u5982\u679c\u6dfb\u52a0\/\u5220\u9664\u5c5e\u6027\u88ab\u7981\u6b62\uff0c\u5e76\u4e14\u6240\u6709\u73b0\u6709\u7684\u5c5e\u6027\u90fd\u5177\u6709\u00a0<code>configurable: false<\/code>\u5219\u8fd4\u56de\u00a0<code>true<\/code>\u3002<br \/>\n<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/isFrozen\">Object.isFrozen(obj)<\/a><br \/>\n\u5982\u679c\u6dfb\u52a0\/\u5220\u9664\/\u66f4\u6539\u5c5e\u6027\u88ab\u7981\u6b62\uff0c\u5e76\u4e14\u6240\u6709\u5f53\u524d\u5c5e\u6027\u90fd\u662f\u00a0<code>configurable: false, writable: false<\/code>\uff0c\u5219\u8fd4\u56de\u00a0<code>true<\/code>\u3002<br \/>\n\u8fd9\u4e9b\u65b9\u6cd5\u5728\u5b9e\u9645\u4e2d\u5f88\u5c11\u4f7f\u7528\u3002<\/p>\n<h2>\u5c5e\u6027\u7684getter \u548c setter<\/h2>\n<p>\u6709\u4e24\u79cd\u7c7b\u578b\u7684\u5bf9\u8c61\u5c5e\u6027\u3002<br \/>\n\u7b2c\u4e00\u79cd\u662f\u00a0<strong>\u6570\u636e\u5c5e\u6027<\/strong>\u3002\u6211\u4eec\u5df2\u7ecf\u77e5\u9053\u5982\u4f55\u4f7f\u7528\u5b83\u4eec\u4e86\u3002\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u6211\u4eec\u4f7f\u7528\u8fc7\u7684\u6240\u6709\u5c5e\u6027\u90fd\u662f\u6570\u636e\u5c5e\u6027\u3002<br \/>\n\u7b2c\u4e8c\u79cd\u7c7b\u578b\u7684\u5c5e\u6027\u662f\u65b0\u4e1c\u897f\u3002\u5b83\u662f\u00a0<strong>\u8bbf\u95ee\u5668\u5c5e\u6027\uff08accessor property\uff09<\/strong>\u3002\u5b83\u4eec\u672c\u8d28\u4e0a\u662f\u7528\u4e8e\u83b7\u53d6\u548c\u8bbe\u7f6e\u503c\u7684\u51fd\u6570\uff0c\u4f46\u4ece\u5916\u90e8\u4ee3\u7801\u6765\u770b\u5c31\u50cf\u5e38\u89c4\u5c5e\u6027\u3002<\/p>\n<h2>getter \u548c setter<\/h2>\n<p>\u8bbf\u95ee\u5668\u5c5e\u6027\u7531 \u201cgetter\u201d \u548c \u201csetter\u201d \u65b9\u6cd5\u8868\u793a\u3002\u5728\u5bf9\u8c61\u5b57\u9762\u91cf\u4e2d\uff0c\u5b83\u4eec\u7528\u00a0<code>get<\/code>\u00a0\u548c\u00a0<code>set<\/code>\u00a0\u8868\u793a\uff1a<\/p>\n<pre><code class=\"language-js\">let obj = {\n  get propName() {\n    \/\/ \u5f53\u8bfb\u53d6 obj.propName \u65f6\uff0cgetter \u8d77\u4f5c\u7528\n  },\n\n  set propName(value) {\n    \/\/ \u5f53\u6267\u884c obj.propName = value \u64cd\u4f5c\u65f6\uff0csetter \u8d77\u4f5c\u7528\n  }\n};\n<\/code><\/pre>\n<p>\u5f53\u8bfb\u53d6\u00a0<code>obj.propName<\/code>\u00a0\u65f6\uff0cgetter \u8d77\u4f5c\u7528\uff0c\u5f53\u00a0<code>obj.propName<\/code>\u00a0\u88ab\u8d4b\u503c\u65f6\uff0csetter \u8d77\u4f5c\u7528\u3002<br \/>\n\u4f8b\u5982\uff0c\u6211\u4eec\u6709\u4e00\u4e2a\u5177\u6709\u00a0<code>name<\/code>\u00a0\u548c\u00a0<code>surname<\/code>\u00a0\u5c5e\u6027\u7684\u5bf9\u8c61\u00a0<code>user<\/code>\u73b0\u5728\u6211\u4eec\u60f3\u6dfb\u52a0\u4e00\u4e2a\u00a0<code>fullName<\/code>\u00a0\u5c5e\u6027\uff0c\u8be5\u5c5e\u6027\u503c\u5e94\u8be5\u4e3a\u00a0<code>&quot;John Smith&quot;<\/code>\u3002\u5f53\u7136\uff0c\u6211\u4eec\u4e0d\u60f3\u590d\u5236\u7c98\u8d34\u5df2\u6709\u7684\u4fe1\u606f\uff0c\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u8bbf\u95ee\u5668\u6765\u5b9e\u73b0\uff1a<\/p>\n<pre><code class=\"language-js\">let user = {\n  name: &quot;John&quot;,\n  surname: &quot;Smith&quot;\n};\n\nlet user = {\n  name: &quot;John&quot;,\n  surname: &quot;Smith&quot;,\n\n  get fullName() {\n    return `${this.name} ${this.surname}`;\n  }\n};\n\nalert(user.fullName); \/\/ John Smith\n<\/code><\/pre>\n<p>\u4ece\u5916\u8868\u770b\uff0c\u8bbf\u95ee\u5668\u5c5e\u6027\u770b\u8d77\u6765\u5c31\u50cf\u4e00\u4e2a\u666e\u901a\u5c5e\u6027\u3002\u8fd9\u5c31\u662f\u8bbf\u95ee\u5668\u5c5e\u6027\u7684\u8bbe\u8ba1\u601d\u60f3\u3002\u6211\u4eec\u4e0d\u4ee5\u51fd\u6570\u7684\u65b9\u5f0f\u00a0<strong>\u8c03\u7528<\/strong>\u00a0<code>user.fullName<\/code>\uff0c\u6211\u4eec\u6b63\u5e38\u00a0<strong>\u8bfb\u53d6<\/strong>\u00a0\u5b83\uff1agetter \u5728\u5e55\u540e\u8fd0\u884c\u3002<br \/>\n\u622a\u81f3\u76ee\u524d\uff0c<code>fullName<\/code>\u00a0\u53ea\u6709\u4e00\u4e2a getter\u3002\u5982\u679c\u6211\u4eec\u5c1d\u8bd5\u8d4b\u503c\u64cd\u4f5c\u00a0<code>user.fullName=<\/code>\uff0c\u5c06\u4f1a\u51fa\u73b0\u9519\u8bef<br \/>\n\u8ba9\u6211\u4eec\u901a\u8fc7\u4e3a\u00a0<code>user.fullName<\/code>\u00a0\u6dfb\u52a0\u4e00\u4e2a setter \u6765\u4fee\u590d\u5b83\uff1a<\/p>\n<pre><code class=\"language-js\">let user = {\n  name: &quot;John&quot;,\n  surname: &quot;Smith&quot;,\n\n  get fullName() {\n    return `${this.name} ${this.surname}`;\n  },\n\n  set fullName(value) {\n    [this.name, this.surname] = value.split(&quot; &quot;);\n  }\n};\n\n\/\/ set fullName \u5c06\u4ee5\u7ed9\u5b9a\u503c\u6267\u884c\nuser.fullName = &quot;Alice Cooper&quot;;\n\nalert(user.name); \/\/ Alice\nalert(user.surname); \/\/ Cooper\n<\/code><\/pre>\n<p>\u73b0\u5728\uff0c\u6211\u4eec\u5c31\u6709\u4e00\u4e2a\u201c\u865a\u62df\u201d\u5c5e\u6027\u3002\u5b83\u662f\u53ef\u8bfb\u4e14\u53ef\u5199\u7684\u3002<\/p>\n<h2>\u8bbf\u95ee\u5668\u63cf\u8ff0\u7b26<\/h2>\n<p>\u8bbf\u95ee\u5668\u5c5e\u6027\u7684\u63cf\u8ff0\u7b26\u4e0e\u6570\u636e\u5c5e\u6027\u7684\u4e0d\u540c\u3002<br \/>\n\u5bf9\u4e8e\u8bbf\u95ee\u5668\u5c5e\u6027\uff0c\u6ca1\u6709\u00a0<code>value<\/code>\u00a0\u548c\u00a0<code>writable<\/code>\uff0c\u4f46\u662f\u6709\u00a0<code>get<\/code>\u00a0\u548c\u00a0<code>set<\/code>\u00a0\u51fd\u6570\u3002<br \/>\n\u6240\u4ee5\u8bbf\u95ee\u5668\u63cf\u8ff0\u7b26\u53ef\u80fd\u6709\uff1a<\/p>\n<ul>\n<li><strong><code>get<\/code><\/strong>\u00a0\u2014\u2014 \u4e00\u4e2a\u6ca1\u6709\u53c2\u6570\u7684\u51fd\u6570\uff0c\u5728\u8bfb\u53d6\u5c5e\u6027\u65f6\u5de5\u4f5c\uff0c<\/li>\n<li><strong><code>set<\/code><\/strong>\u00a0\u2014\u2014 \u5e26\u6709\u4e00\u4e2a\u53c2\u6570\u7684\u51fd\u6570\uff0c\u5f53\u5c5e\u6027\u88ab\u8bbe\u7f6e\u65f6\u8c03\u7528\uff0c<\/li>\n<li><strong><code>enumerable<\/code><\/strong>\u00a0\u2014\u2014 \u4e0e\u6570\u636e\u5c5e\u6027\u7684\u76f8\u540c\uff0c<\/li>\n<li><strong><code>configurable<\/code><\/strong>\u00a0\u2014\u2014 \u4e0e\u6570\u636e\u5c5e\u6027\u7684\u76f8\u540c\u3002<br \/>\n\u4f8b\u5982\uff0c\u8981\u4f7f\u7528\u00a0<code>defineProperty<\/code>\u00a0\u521b\u5efa\u4e00\u4e2a\u00a0<code>fullName<\/code>\u00a0\u8bbf\u95ee\u5668\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u00a0<code>get<\/code>\u00a0\u548c\u00a0<code>set<\/code>\u00a0\u6765\u4f20\u9012\u63cf\u8ff0\u7b26\uff1a<\/li>\n<\/ul>\n<pre><code class=\"language-js\">let user = {\n  name: &quot;John&quot;,\n  surname: &quot;Smith&quot;\n};\n\nObject.defineProperty(user, 'fullName', {\n  get() {\n    return `${this.name} ${this.surname}`;\n  },\n\n  set(value) {\n    [this.name, this.surname] = value.split(&quot; &quot;);\n  }\n});\n\nalert(user.fullName); \/\/ John Smith\n\nfor(let key in user) alert(key); \/\/ name, surname\n<\/code><\/pre>\n<p>\u8bf7\u6ce8\u610f\uff0c\u4e00\u4e2a\u5c5e\u6027\u8981\u4e48\u662f\u8bbf\u95ee\u5668\uff08\u5177\u6709\u00a0<code>get\/set<\/code>\u00a0\u65b9\u6cd5\uff09\uff0c\u8981\u4e48\u662f\u6570\u636e\u5c5e\u6027\uff08\u5177\u6709\u00a0<code>value<\/code>\uff09\uff0c\u4f46\u4e0d\u80fd\u4e24\u8005\u90fd\u662f\u3002<br \/>\n\u5982\u679c\u6211\u4eec\u8bd5\u56fe\u5728\u540c\u4e00\u4e2a\u63cf\u8ff0\u7b26\u4e2d\u540c\u65f6\u63d0\u4f9b\u00a0<code>get<\/code>\u00a0\u548c\u00a0<code>value<\/code>\uff0c\u5219\u4f1a\u51fa\u73b0\u9519\u8bef\uff1a<\/p>\n<h2>\u66f4\u806a\u660e\u7684 getter\/setter<\/h2>\n<p>getter\/setter \u53ef\u4ee5\u7528\u4f5c\u201c\u771f\u5b9e\u201d\u5c5e\u6027\u503c\u7684\u5305\u88c5\u5668\uff0c\u4ee5\u4fbf\u5bf9\u5b83\u4eec\u8fdb\u884c\u66f4\u591a\u7684\u63a7\u5236\u3002<br \/>\n\u4f8b\u5982\uff0c\u5982\u679c\u6211\u4eec\u60f3\u7981\u6b62\u592a\u77ed\u7684\u00a0<code>user<\/code>\u00a0\u7684 name\uff0c\u6211\u4eec\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a setter\u00a0<code>name<\/code>\uff0c\u5e76\u5c06\u503c\u5b58\u50a8\u5728\u4e00\u4e2a\u5355\u72ec\u7684\u5c5e\u6027\u00a0<code>_name<\/code>\u00a0\u4e2d\uff1a<\/p>\n<pre><code class=\"language-js\">let user = {\n  get name() {\n    return this._name;\n  },\n\n  set name(value) {\n    if (value.length &lt; 4) {\n      alert(&quot;Name is too short, need at least 4 characters&quot;);\n      return;\n    }\n    this._name = value;\n  }\n};\n\nuser.name = &quot;Pete&quot;;\nalert(user.name); \/\/ Pete\n\nuser.name = &quot;&quot;; \/\/ Name \u592a\u77ed\u4e86\u2026\u2026\n<\/code><\/pre>\n<p>\u6240\u4ee5\uff0cname \u88ab\u5b58\u50a8\u5728 _name \u5c5e\u6027\u4e2d\uff0c\u5e76\u901a\u8fc7 getter \u548c setter \u8fdb\u884c\u8bbf\u95ee\u3002<br \/>\n\u4ece\u6280\u672f\u4e0a\u8bb2\uff0c\u5916\u90e8\u4ee3\u7801\u53ef\u4ee5\u4f7f\u7528 user._name \u76f4\u63a5\u8bbf\u95ee name\u3002\u4f46\u662f\uff0c\u8fd9\u513f\u6709\u4e00\u4e2a\u4f17\u6240\u5468\u77e5\u7684\u7ea6\u5b9a\uff0c\u5373\u4ee5\u4e0b\u5212\u7ebf &quot;_&quot; \u5f00\u5934\u7684\u5c5e\u6027\u662f\u5185\u90e8\u5c5e\u6027\uff0c\u4e0d\u5e94\u8be5\u4ece\u5bf9\u8c61\u5916\u90e8\u8fdb\u884c\u8bbf\u95ee\u3002<\/p>\n<h2>\u517c\u5bb9\u6027<\/h2>\n<p>\u8bbf\u95ee\u5668\u7684\u4e00\u5927\u7528\u9014\u662f\uff0c\u5b83\u4eec\u5141\u8bb8\u968f\u65f6\u901a\u8fc7\u4f7f\u7528 getter \u548c setter \u66ff\u6362\u201c\u6b63\u5e38\u7684\u201d\u6570\u636e\u5c5e\u6027\uff0c\u6765\u63a7\u5236\u548c\u8c03\u6574\u8fd9\u4e9b\u5c5e\u6027\u7684\u884c\u4e3a\u3002<br \/>\n\u60f3\u8c61\u4e00\u4e0b\uff0c\u6211\u4eec\u5f00\u59cb\u4f7f\u7528\u6570\u636e\u5c5e\u6027\u00a0<code>name<\/code>\u00a0\u548c\u00a0<code>age<\/code>\u00a0\u6765\u5b9e\u73b0 user \u5bf9\u8c61\uff1a<\/p>\n<pre><code class=\"language-js\">function User(name, age) {\n  this.name = name;\n  this.age = age;\n}\n\nlet john = new User(&quot;John&quot;, 25);\n\nalert( john.age ); \/\/ 25\n<\/code><\/pre>\n<p>\u2026\u2026\u4f46\u8fdf\u65e9\uff0c\u60c5\u51b5\u53ef\u80fd\u4f1a\u53d1\u751f\u53d8\u5316\u3002\u6211\u4eec\u53ef\u80fd\u4f1a\u51b3\u5b9a\u5b58\u50a8\u00a0<code>birthday<\/code>\uff0c\u800c\u4e0d\u662f\u00a0<code>age<\/code>\uff0c\u56e0\u4e3a\u5b83\u66f4\u7cbe\u786e\uff0c\u66f4\u65b9\u4fbf<\/p>\n<pre><code class=\"language-js\">function User(name, birthday) {\n  this.name = name;\n  this.birthday = birthday;\n}\n\nlet john = new User(&quot;John&quot;, new Date(1992, 6, 1));\n<\/code><\/pre>\n<p>\u73b0\u5728\u5e94\u8be5\u5982\u4f55\u5904\u7406\u4ecd\u4f7f\u7528\u00a0<code>age<\/code>\u00a0\u5c5e\u6027\u7684\u65e7\u4ee3\u7801\u5462\uff1f<br \/>\n\u6211\u4eec\u53ef\u4ee5\u5c1d\u8bd5\u627e\u5230\u6240\u6709\u8fd9\u4e9b\u5730\u65b9\u5e76\u4fee\u6539\u5b83\u4eec\uff0c\u4f46\u8fd9\u4f1a\u82b1\u8d39\u5f88\u591a\u65f6\u95f4\uff0c\u800c\u4e14\u5982\u679c\u5176\u4ed6\u5f88\u591a\u4eba\u90fd\u5728\u4f7f\u7528\u8be5\u4ee3\u7801\uff0c\u90a3\u4e48\u53ef\u80fd\u5f88\u96be\u5b8c\u6210\u6240\u6709\u4fee\u6539\u3002\u800c\u4e14\uff0c<code>user<\/code>\u00a0\u4e2d\u6709\u00a0<code>age<\/code>\u00a0\u662f\u4e00\u4ef6\u597d\u4e8b\uff0c\u5bf9\u5427\uff1f<br \/>\n\u90a3\u6211\u4eec\u5c31\u628a\u5b83\u4fdd\u7559\u4e0b\u6765\u5427\u3002<br \/>\n\u4e3a\u00a0<code>age<\/code>\u00a0\u6dfb\u52a0\u4e00\u4e2a getter \u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff1a<\/p>\n<pre><code class=\"language-js\">function User(name, birthday) {\n  this.name = name;\n  this.birthday = birthday;\n\n  \/\/ \u5e74\u9f84\u662f\u6839\u636e\u5f53\u524d\u65e5\u671f\u548c\u751f\u65e5\u8ba1\u7b97\u5f97\u51fa\u7684\n  Object.defineProperty(this, &quot;age&quot;, {\n    get() {\n      let todayYear = new Date().getFullYear();\n      return todayYear - this.birthday.getFullYear();\n    }\n  });\n}\n\nlet john = new User(&quot;John&quot;, new Date(1992, 6, 1));\n\nalert( john.birthday ); \/\/ birthday \u662f\u53ef\u8bbf\u95ee\u7684\nalert( john.age );      \/\/ \u2026\u2026age \u4e5f\u662f\u53ef\u8bbf\u95ee\u7684\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u5c5e\u6027\u6807\u5fd7\u548c\u5c5e\u6027\u63cf\u8ff0\u7b26 \u6211\u4eec\u77e5\u9053\uff0c\u5bf9\u8c61\u53ef\u4ee5\u5b58\u50a8\u5c5e\u6027\u3002 \u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u5c5e\u6027\u5bf9\u6211\u4eec\u6765\u8bf4\u53ea\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u201c\u952e\u503c\u201d\u5bf9\u3002\u4f46\u5bf9\u8c61 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-632","post","type-post","status-publish","format-standard","hentry","category-front-end"],"_links":{"self":[{"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/posts\/632","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/levin.ink\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=632"}],"version-history":[{"count":2,"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/posts\/632\/revisions"}],"predecessor-version":[{"id":639,"href":"https:\/\/levin.ink\/index.php?rest_route=\/wp\/v2\/posts\/632\/revisions\/639"}],"wp:attachment":[{"href":"https:\/\/levin.ink\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/levin.ink\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/levin.ink\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}