{"id":1386,"date":"2024-06-02T22:33:07","date_gmt":"2024-06-02T22:33:07","guid":{"rendered":""},"modified":"2024-06-05T03:10:11","modified_gmt":"2024-06-04T19:10:11","slug":"javascript%e6%b7%b1%e5%85%a5%e4%b9%8b%e6%89%a7%e8%a1%8c%e4%b8%8a%e4%b8%8b%e6%96%87","status":"publish","type":"post","link":"https:\/\/www.lccc.top\/?p=1386","title":{"rendered":"JavaScript\u6df1\u5165\u4e4b\u6267\u884c\u4e0a\u4e0b\u6587"},"content":{"rendered":"<td class=\"d-block comment-body markdown-body  js-comment-body\">\n<h1 dir=\"auto\">\u524d\u8a00<\/h1>\n<p dir=\"auto\">\u5728<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/4\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/4\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u300b<\/a>\u4e2d\u8bb2\u5230\uff0c\u5f53 JavaScript \u4ee3\u7801\u6267\u884c\u4e00\u6bb5\u53ef\u6267\u884c\u4ee3\u7801(executable code)\u65f6\uff0c\u4f1a\u521b\u5efa\u5bf9\u5e94\u7684\u6267\u884c\u4e0a\u4e0b\u6587(execution context)\u3002<\/p>\n<p dir=\"auto\">\u5bf9\u4e8e\u6bcf\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u90fd\u6709\u4e09\u4e2a\u91cd\u8981\u5c5e\u6027\uff1a<\/p>\n<ul dir=\"auto\">\n<li>\u53d8\u91cf\u5bf9\u8c61(Variable object\uff0cVO)<\/li>\n<li>\u4f5c\u7528\u57df\u94fe(Scope chain)<\/li>\n<li>this<\/li>\n<\/ul>\n<p dir=\"auto\">\u7136\u540e\u5206\u522b\u5728<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/5\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/5\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u53d8\u91cf\u5bf9\u8c61\u300b<\/a>\u3001<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/6\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/6\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u4f5c\u7528\u57df\u94fe\u300b<\/a>\u3001<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/7\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/7\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u4eceECMAScript\u89c4\u8303\u89e3\u8bfbthis\u300b<\/a>\u4e2d\u8bb2\u89e3\u4e86\u8fd9\u4e09\u4e2a\u5c5e\u6027\u3002<\/p>\n<p dir=\"auto\">\u9605\u8bfb\u672c\u6587\u524d\uff0c\u5982\u679c\u5bf9\u4ee5\u4e0a\u7684\u6982\u5ff5\u4e0d\u662f\u5f88\u6e05\u695a\uff0c\u5e0c\u671b\u5148\u9605\u8bfb\u8fd9\u4e9b\u6587\u7ae0\u3002<\/p>\n<p dir=\"auto\">\u56e0\u4e3a\uff0c\u8fd9\u4e00\u7bc7\uff0c\u6211\u4eec\u4f1a\u7ed3\u5408\u7740\u6240\u6709\u5185\u5bb9\uff0c\u8bb2\u8bb2\u6267\u884c\u4e0a\u4e0b\u6587\u7684\u5177\u4f53\u5904\u7406\u8fc7\u7a0b\u3002<\/p>\n<h2 dir=\"auto\">\u601d\u8003\u9898<\/h2>\n<p dir=\"auto\">\u5728<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/3\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/3\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u8bcd\u6cd5\u4f5c\u7528\u57df\u548c\u52a8\u6001\u4f5c\u7528\u57df\u300b<\/a>\u4e2d\uff0c\u63d0\u51fa\u8fd9\u6837\u4e00\u9053\u601d\u8003\u9898\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content='var scope = \"global scope\";\nfunction checkscope(){\n    var scope = \"local scope\";\n    function f(){\n        return scope;\n    }\n    return f();\n}\ncheckscope();'><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"global scope\"<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"local scope\"<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">scope<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n<span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content='var scope = \"global scope\";\nfunction checkscope(){\n    var scope = \"local scope\";\n    function f(){\n        return scope;\n    }\n    return f;\n}\ncheckscope()();'><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"global scope\"<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"local scope\"<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">scope<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n<span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u4e24\u6bb5\u4ee3\u7801\u90fd\u4f1a\u6253\u5370&#8217;local scope&#8217;\u3002\u867d\u7136\u4e24\u6bb5\u4ee3\u7801\u6267\u884c\u7684\u7ed3\u679c\u4e00\u6837\uff0c\u4f46\u662f\u4e24\u6bb5\u4ee3\u7801\u7a76\u7adf\u6709\u54ea\u4e9b\u4e0d\u540c\u5462\uff1f<\/p>\n<p dir=\"auto\">\u7d27\u63a5\u7740\u5c31\u5728\u4e0b\u4e00\u7bc7<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/4\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/4\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u300b<\/a>\u4e2d\uff0c\u8bb2\u5230\u4e86\u4e24\u8005\u7684\u533a\u522b\u5728\u4e8e\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u7684\u53d8\u5316\u4e0d\u4e00\u6837\uff0c\u7136\u800c\uff0c\u5982\u679c\u662f\u8fd9\u6837\u7b3c\u7edf\u7684\u56de\u7b54\uff0c\u4f9d\u7136\u663e\u5f97\u4e0d\u591f\u8be6\u7ec6\uff0c\u672c\u7bc7\u5c31\u4f1a\u8be6\u7ec6\u7684\u89e3\u6790\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u548c\u6267\u884c\u4e0a\u4e0b\u6587\u7684\u5177\u4f53\u53d8\u5316\u8fc7\u7a0b\u3002<\/p>\n<h2 dir=\"auto\">\u5177\u4f53\u6267\u884c\u5206\u6790<\/h2>\n<p dir=\"auto\">\u6211\u4eec\u5206\u6790\u7b2c\u4e00\u6bb5\u4ee3\u7801\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content='var scope = \"global scope\";\nfunction checkscope(){\n    var scope = \"local scope\";\n    function f(){\n        return scope;\n    }\n    return f();\n}\ncheckscope();'><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"global scope\"<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"local scope\"<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">scope<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n<span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u6267\u884c\u8fc7\u7a0b\u5982\u4e0b\uff1a<\/p>\n<p dir=\"auto\">1.\u6267\u884c\u5168\u5c40\u4ee3\u7801\uff0c\u521b\u5efa\u5168\u5c40\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u5168\u5c40\u4e0a\u4e0b\u6587\u88ab\u538b\u5165\u6267\u884c\u4e0a\u4e0b\u6587\u6808<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    ECStack = [\n        globalContext\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-v\">ECStack<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n        <span class=\"pl-s1\">globalContext<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">2.\u5168\u5c40\u4e0a\u4e0b\u6587\u521d\u59cb\u5316<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    globalContext = {\n        VO: [global],\n        Scope: [globalContext.VO],\n        this: globalContext.VO\n    }\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-s1\">globalContext<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-c1\">VO<\/span>: <span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">global<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">Scope<\/span>: <span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">globalContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">VO<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">this<\/span>: <span class=\"pl-s1\">globalContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">VO<\/span>\n    <span class=\"pl-kos\">}<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">2.\u521d\u59cb\u5316\u7684\u540c\u65f6\uff0ccheckscope \u51fd\u6570\u88ab\u521b\u5efa\uff0c\u4fdd\u5b58\u4f5c\u7528\u57df\u94fe\u5230\u51fd\u6570\u7684\u5185\u90e8\u5c5e\u6027[[scope]]<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    checkscope.[[scope]] = [\n      globalContext.VO\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-s1\">checkscope<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\"><\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">scope<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n      <span class=\"pl-s1\">globalContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">VO<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">3.\u6267\u884c checkscope \u51fd\u6570\uff0c\u521b\u5efa checkscope \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\uff0ccheckscope \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\u88ab\u538b\u5165\u6267\u884c\u4e0a\u4e0b\u6587\u6808<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    ECStack = [\n        checkscopeContext,\n        globalContext\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-v\">ECStack<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n        <span class=\"pl-s1\">checkscopeContext<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-s1\">globalContext<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">4.checkscope \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\u521d\u59cb\u5316\uff1a<\/p>\n<ol dir=\"auto\">\n<li>\u590d\u5236\u51fd\u6570 [[scope]] \u5c5e\u6027\u521b\u5efa\u4f5c\u7528\u57df\u94fe\uff0c<\/li>\n<li>\u7528 arguments \u521b\u5efa\u6d3b\u52a8\u5bf9\u8c61\uff0c<\/li>\n<li>\u521d\u59cb\u5316\u6d3b\u52a8\u5bf9\u8c61\uff0c\u5373\u52a0\u5165\u5f62\u53c2\u3001\u51fd\u6570\u58f0\u660e\u3001\u53d8\u91cf\u58f0\u660e\uff0c<\/li>\n<li>\u5c06\u6d3b\u52a8\u5bf9\u8c61\u538b\u5165 checkscope \u4f5c\u7528\u57df\u94fe\u9876\u7aef\u3002<\/li>\n<\/ol>\n<p dir=\"auto\">\u540c\u65f6 f \u51fd\u6570\u88ab\u521b\u5efa\uff0c\u4fdd\u5b58\u4f5c\u7528\u57df\u94fe\u5230 f \u51fd\u6570\u7684\u5185\u90e8\u5c5e\u6027[[scope]]<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    checkscopeContext = {\n        AO: {\n            arguments: {\n                length: 0\n            },\n            scope: undefined,\n            f: reference to function f(){}\n        },\n        Scope: [AO, globalContext.VO],\n        this: undefined\n    }\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-s1\">checkscopeContext<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-c1\">AO<\/span>: <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-c1\">arguments<\/span>: <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-c1\">length<\/span>: <span class=\"pl-c1\">0<\/span>\n            <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span>\n            <span class=\"pl-c1\">scope<\/span>: <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">,<\/span>\n            <span class=\"pl-en\">f<\/span>: <span class=\"pl-s1\">reference<\/span> <span class=\"pl-s1\">to<\/span> <span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">Scope<\/span>: <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">AO<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">globalContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">VO<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">this<\/span>: <span class=\"pl-c1\">undefined<\/span>\n    <span class=\"pl-kos\">}<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">5.\u6267\u884c f \u51fd\u6570\uff0c\u521b\u5efa f \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\uff0cf \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\u88ab\u538b\u5165\u6267\u884c\u4e0a\u4e0b\u6587\u6808<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    ECStack = [\n        fContext,\n        checkscopeContext,\n        globalContext\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-v\">ECStack<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n        <span class=\"pl-s1\">fContext<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-s1\">checkscopeContext<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-s1\">globalContext<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">6.f \u51fd\u6570\u6267\u884c\u4e0a\u4e0b\u6587\u521d\u59cb\u5316, \u4ee5\u4e0b\u8ddf\u7b2c 4 \u6b65\u76f8\u540c\uff1a<\/p>\n<ol dir=\"auto\">\n<li>\u590d\u5236\u51fd\u6570 [[scope]] \u5c5e\u6027\u521b\u5efa\u4f5c\u7528\u57df\u94fe<\/li>\n<li>\u7528 arguments \u521b\u5efa\u6d3b\u52a8\u5bf9\u8c61<\/li>\n<li>\u521d\u59cb\u5316\u6d3b\u52a8\u5bf9\u8c61\uff0c\u5373\u52a0\u5165\u5f62\u53c2\u3001\u51fd\u6570\u58f0\u660e\u3001\u53d8\u91cf\u58f0\u660e<\/li>\n<li>\u5c06\u6d3b\u52a8\u5bf9\u8c61\u538b\u5165 f \u4f5c\u7528\u57df\u94fe\u9876\u7aef<\/li>\n<\/ol>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    fContext = {\n        AO: {\n            arguments: {\n                length: 0\n            }\n        },\n        Scope: [AO, checkscopeContext.AO, globalContext.VO],\n        this: undefined\n    }\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-s1\">fContext<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-c1\">AO<\/span>: <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-c1\">arguments<\/span>: <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-c1\">length<\/span>: <span class=\"pl-c1\">0<\/span>\n            <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">Scope<\/span>: <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">AO<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">checkscopeContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">AO<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">globalContext<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">VO<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-c1\">this<\/span>: <span class=\"pl-c1\">undefined<\/span>\n    <span class=\"pl-kos\">}<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">7.f \u51fd\u6570\u6267\u884c\uff0c\u6cbf\u7740\u4f5c\u7528\u57df\u94fe\u67e5\u627e scope \u503c\uff0c\u8fd4\u56de scope \u503c<\/p>\n<p dir=\"auto\">8.f \u51fd\u6570\u6267\u884c\u5b8c\u6bd5\uff0cf \u51fd\u6570\u4e0a\u4e0b\u6587\u4ece\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u4e2d\u5f39\u51fa<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    ECStack = [\n        checkscopeContext,\n        globalContext\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-v\">ECStack<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n        <span class=\"pl-s1\">checkscopeContext<\/span><span class=\"pl-kos\">,<\/span>\n        <span class=\"pl-s1\">globalContext<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">9.checkscope \u51fd\u6570\u6267\u884c\u5b8c\u6bd5\uff0ccheckscope \u6267\u884c\u4e0a\u4e0b\u6587\u4ece\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u4e2d\u5f39\u51fa<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"    ECStack = [\n        globalContext\n    ];\"><\/p>\n<pre class=\"notranslate\">    <span class=\"pl-v\">ECStack<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span>\n        <span class=\"pl-s1\">globalContext<\/span>\n    <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u7b2c\u4e8c\u6bb5\u4ee3\u7801\u5c31\u7559\u7ed9\u5927\u5bb6\u53bb\u5c1d\u8bd5\u6a21\u62df\u5b83\u7684\u6267\u884c\u8fc7\u7a0b\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content='var scope = \"global scope\";\nfunction checkscope(){\n    var scope = \"local scope\";\n    function f(){\n        return scope;\n    }\n    return f;\n}\ncheckscope()();'><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"global scope\"<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">scope<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"local scope\"<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">scope<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n<span class=\"pl-en\">checkscope<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u4e0d\u8fc7\uff0c\u5728\u4e0b\u4e00\u7bc7\u300aJavaScript\u6df1\u5165\u4e4b\u95ed\u5305\u300b\u4e2d\u4e5f\u4f1a\u63d0\u53ca\u8fd9\u6bb5\u4ee3\u7801\u7684\u6267\u884c\u8fc7\u7a0b\u3002<\/p>\n<h2 dir=\"auto\">\u4e0b\u4e00\u7bc7\u6587\u7ae0<\/h2>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/9\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/9\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u95ed\u5305\u300b<\/a><\/p>\n<h2 dir=\"auto\">\u76f8\u5173\u94fe\u63a5<\/h2>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/3\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/3\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u8bcd\u6cd5\u4f5c\u7528\u57df\u548c\u52a8\u6001\u4f5c\u7528\u57df\u300b<\/a><\/p>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/4\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/4\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u300b<\/a><\/p>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/5\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/5\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u53d8\u91cf\u5bf9\u8c61\u300b<\/a><\/p>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/6\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/6\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u4f5c\u7528\u57df\u94fe\u300b<\/a><\/p>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/7\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/7\/hovercard\">\u300aJavaScript\u6df1\u5165\u4e4b\u4eceECMAScript\u89c4\u8303\u89e3\u8bfbthis\u300b<\/a><\/p>\n<h2 dir=\"auto\">\u91cd\u8981\u53c2\u8003<\/h2>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/kuitos\/kuitos.github.io\/issues\/18\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/kuitos\/kuitos.github.io\/issues\/18\/hovercard\">\u300a\u4e00\u9053js\u9762\u8bd5\u9898\u5f15\u53d1\u7684\u601d\u8003\u300b<\/a><\/p>\n<p dir=\"auto\">\u672c\u6587\u5199\u7684\u592a\u597d\uff0c\u7ed9\u4e86\u6211\u5f88\u591a\u542f\u53d1\u3002\u611f\u6fc0\u4e0d\u5c3d\uff01<\/p>\n<h2 dir=\"auto\">\u6df1\u5165\u7cfb\u5217<\/h2>\n<p dir=\"auto\">JavaScript\u6df1\u5165\u7cfb\u5217\u76ee\u5f55\u5730\u5740\uff1a<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\">https:\/\/github.com\/mqyqingfeng\/Blog<\/a>\u3002<\/p>\n<p dir=\"auto\">JavaScript\u6df1\u5165\u7cfb\u5217\u9884\u8ba1\u5199\u5341\u4e94\u7bc7\u5de6\u53f3\uff0c\u65e8\u5728\u5e2e\u5927\u5bb6\u634b\u987aJavaScript\u5e95\u5c42\u77e5\u8bc6\uff0c\u91cd\u70b9\u8bb2\u89e3\u5982\u539f\u578b\u3001\u4f5c\u7528\u57df\u3001\u6267\u884c\u4e0a\u4e0b\u6587\u3001\u53d8\u91cf\u5bf9\u8c61\u3001this\u3001\u95ed\u5305\u3001\u6309\u503c\u4f20\u9012\u3001call\u3001apply\u3001bind\u3001new\u3001\u7ee7\u627f\u7b49\u96be\u70b9\u6982\u5ff5\u3002<\/p>\n<p dir=\"auto\">\u5982\u679c\u6709\u9519\u8bef\u6216\u8005\u4e0d\u4e25\u8c28\u7684\u5730\u65b9\uff0c\u8bf7\u52a1\u5fc5\u7ed9\u4e88\u6307\u6b63\uff0c\u5341\u5206\u611f\u8c22\u3002\u5982\u679c\u559c\u6b22\u6216\u8005\u6709\u6240\u542f\u53d1\uff0c\u6b22\u8fcestar\uff0c\u5bf9\u4f5c\u8005\u4e5f\u662f\u4e00\u79cd\u9f13\u52b1\u3002<\/p>\n<\/td>\n<p>\u6587\u7ae0\u8f6c\u8f7d\u81ea<a href='https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/8'>https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/8<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u524d\u8a00 \u5728\u300aJavaScript\u6df1\u5165\u4e4b\u6267\u884c\u4e0a\u4e0b\u6587\u6808\u300b\u4e2d\u8bb2\u5230\uff0c\u5f53 JavaScript \u4ee3\u7801\u6267\u884c\u4e00\u6bb5\u53ef\u6267\u884c\u4ee3\u7801(executable code)\u65f6\uff0c\u4f1a\u521b\u5efa\u5bf9\u5e94\u7684\u6267\u884c&#8230;<\/p>\n<p class=\"read-more\"><a class=\"btn btn-default\" href=\"https:\/\/www.lccc.top\/?p=1386\"> Read More<span class=\"screen-reader-text\">  Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1386","post","type-post","status-publish","format-standard","hentry","category-learn"],"_links":{"self":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1386"}],"collection":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1386"}],"version-history":[{"count":1,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1386\/revisions"}],"predecessor-version":[{"id":1495,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1386\/revisions\/1495"}],"wp:attachment":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1386"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1386"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1386"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}