{"id":3248,"date":"2021-05-19T22:27:46","date_gmt":"2021-05-19T14:27:46","guid":{"rendered":"http:\/\/www.yuguoxy.com\/geekhome\/?p=3248"},"modified":"2021-05-19T22:27:46","modified_gmt":"2021-05-19T14:27:46","slug":"javascript%e5%85%a8%e5%b1%80%e5%8f%98%e9%87%8f%e4%b8%8e%e5%b1%80%e9%83%a8%e5%8f%98%e9%87%8f","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=3248","title":{"rendered":"JavaScript\u5168\u5c40\u53d8\u91cf\u4e0e\u5c40\u90e8\u53d8\u91cf"},"content":{"rendered":"

\u5728\u5b66\u4e60JavaScript\u7684\u53d8\u91cf\u4f5c\u7528\u57df\u4e4b\u524d\uff0c\u6211\u4eec\u5e94\u5f53\u660e\u786e\u51e0\u70b9\uff1a<\/p>\n

JavaScript\u7684\u53d8\u91cf\u4f5c\u7528\u57df\u662f\u57fa\u4e8e\u5176\u7279\u6709\u7684\u4f5c\u7528\u57df\u94fe\u7684\u3002
\nJavaScript\u6ca1\u6709\u5757\u7ea7\u4f5c\u7528\u57df\u3002
\n\u51fd\u6570\u4e2d\u58f0\u660e\u7684\u53d8\u91cf\u5728\u6574\u4e2a\u51fd\u6570\u4e2d\u90fd\u6709\u5b9a\u4e49\u3002<\/p>\n

1\u3001JavaScript\u7684\u4f5c\u7528\u57df\u94fe<\/strong><\/h3>\n

\u9996\u5148\u770b\u4e0b\u4e0b\u9762\u8fd9\u6bb5\u4ee3\u7801\uff1a<\/p>\n

 <\/p>\n

<script type="text\/javascript">\r\n    var rain = 1;\r\n    function rainman(){\r\n        var man = 2;\r\n        function inner(){\r\n            var innerVar = 4;\r\n            alert(rain);\r\n        }\r\n        inner();    \/\/\u8c03\u7528inner\u51fd\u6570\r\n    }\r\n    rainman();    \/\/\u8c03\u7528rainman\u51fd\u6570\r\n<\/script>\r\n<\/code><\/pre>\n
\u89c2\u5bdfalert(rain);\u8fd9\u53e5\u4ee3\u7801\u3002JavaScript\u9996\u5148\u5728inner\u51fd\u6570\u4e2d\u67e5\u627e\u662f\u5426\u5b9a\u4e49\u4e86\u53d8\u91cfrain\uff0c\u5982\u679c\u5b9a\u4e49\u4e86\u5219\u4f7f\u7528inner\u51fd\u6570\u4e2d\u7684rain\u53d8\u91cf\uff1b<\/p>\n
\u5982\u679cinner\u51fd\u6570\u4e2d\u6ca1\u6709\u5b9a\u4e49rain\u53d8\u91cf\uff0cJavaScript\u5219\u4f1a\u7ee7\u7eed\u5728rainman\u51fd\u6570\u4e2d\u67e5\u627e\u662f\u5426\u5b9a\u4e49\u4e86rain\u53d8\u91cf\uff0c\u5728\u8fd9\u6bb5\u4ee3\u7801\u4e2drainman\u51fd\u6570\u4f53\u5185\u6ca1\u6709\u5b9a\u4e49rain\u53d8\u91cf\uff0c\u5219JavaScript\u5f15\u64ce\u4f1a\u7ee7\u7eed\u5411\u4e0a\uff08\u5168\u5c40\u5bf9\u8c61\uff09\u67e5\u627e\u662f\u5426\u5b9a\u4e49\u4e86rain\uff1b\u5728\u5168\u5c40\u5bf9\u8c61\u4e2d\u6211\u4eec\u5b9a\u4e49\u4e86rain = 1\uff0c\u56e0\u6b64\u6700\u7ec8\u7ed3\u679c\u4f1a\u5f39\u51fa'1'\u3002<\/p>\n
\u4f5c\u7528\u57df\u94fe\uff1aJavaScript\u9700\u8981\u67e5\u8be2\u4e00\u4e2a\u53d8\u91cfx\u65f6\uff0c\u9996\u5148\u4f1a\u67e5\u627e\u4f5c\u7528\u57df\u94fe\u7684\u7b2c\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5982\u679c\u4ee5\u7b2c\u4e00\u4e2a\u5bf9\u8c61\u6ca1\u6709\u5b9a\u4e49x\u53d8\u91cf\uff0cJavaScript\u4f1a\u7ee7\u7eed\u67e5\u627e\u6709\u6ca1\u6709\u5b9a\u4e49x\u53d8\u91cf\uff0c\u5982\u679c\u7b2c\u4e8c\u4e2a\u5bf9\u8c61\u6ca1\u6709\u5b9a\u4e49\u5219\u4f1a\u7ee7\u7eed\u67e5\u627e\uff0c\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n
\u4e0a\u9762\u7684\u4ee3\u7801\u6d89\u53ca\u5230\u4e86\u4e09\u4e2a\u4f5c\u7528\u57df\u94fe\u5bf9\u8c61\uff0c\u4f9d\u6b21\u662f\uff1ainner\u3001rainman\u3001window\u3002<\/p>\n
2\u3001\u51fd\u6570\u4f53\u5185\u90e8\uff0c\u5c40\u90e8\u53d8\u91cf\u7684\u4f18\u5148\u7ea7\u6bd4\u540c\u540d\u7684\u5168\u5c40\u53d8\u91cf\u9ad8\u3002<\/strong><\/h3>\n
 <\/p>\n
<script type="text\/javascript">\r\n    var rain = 1;    \/\/\u5b9a\u4e49\u5168\u5c40\u53d8\u91cf rain\r\n    function check(){\r\n        var rain = 100;    \/\/\u5b9a\u4e49\u5c40\u90e8\u53d8\u91cfrain\r\n        alert( rain );       \/\/\u8fd9\u91cc\u4f1a\u5f39\u51fa 100\r\n    }\r\n    check();\r\n    alert( rain );    \/\/\u8fd9\u91cc\u4f1a\u5f39\u51fa1\r\n<\/script>\r\n<\/code><\/pre>\n
3\u3001JavaScript\u6ca1\u6709\u5757\u7ea7\u4f5c\u7528\u57df\u3002<\/strong><\/h3>\n
\u8fd9\u4e00\u70b9\u4e5f\u662fJavaScript\u76f8\u6bd4\u5176\u5b83\u8bed\u8a00\u8f83\u7075\u6d3b\u7684\u90e8\u5206\u3002\u4ed4\u7ec6\u89c2\u5bdf\u4e0b\u9762\u7684\u4ee3\u7801\uff0c\u4f60\u4f1a\u53d1\u73b0\u53d8\u91cfi\u3001j\u3001k\u4f5c\u7528\u57df\u662f\u76f8\u540c\u7684\uff0c\u4ed6\u4eec\u5728\u6574\u4e2arain\u51fd\u6570\u4f53\u5185\u90fd\u662f\u5168\u5c40\u7684\u3002<\/p>\n
 <\/p>\n
<script type="text\/javascript">\r\n    function rainman(){\r\n        \/\/ rainman\u51fd\u6570\u4f53\u5185\u5b58\u5728\u4e09\u4e2a\u5c40\u90e8\u53d8\u91cf i j k\r\n        var i = 0;\r\n        if ( 1 ) {\r\n            var j = 0;\r\n            for(var k = 0; k < 3; k++) {\r\n                alert( k );    \/\/\u5206\u522b\u5f39\u51fa 0 1 2\r\n            }\r\n            alert( k );        \/\/\u5f39\u51fa3\r\n        }\r\n        alert( j );            \/\/\u5f39\u51fa0\r\n    }\r\n<\/script>\r\n<\/code><\/pre>\n
4\u3001\u51fd\u6570\u4e2d\u58f0\u660e\u7684\u53d8\u91cf\u5728\u6574\u4e2a\u51fd\u6570\u4e2d\u90fd\u6709\u5b9a\u4e49\u3002<\/strong><\/h3>\n
\u9996\u5148\u89c2\u5bdf\u8fd9\u6bb5\u4ee3\u7801\uff1a<\/p>\n
 <\/p>\n
<script type="text\/javascript">\r\n    function rain(){\r\n        var x = 1;\r\n        function man(){\r\n            x = 100;\r\n        }\r\n        man();        \/\/\u8c03\u7528man\r\n        alert( x );    \/\/\u8fd9\u91cc\u4f1a\u5f39\u51fa 100\r\n    }\r\n    rain();    \/\/\u8c03\u7528rain\r\n<\/script>\r\n<\/code><\/pre>\n
\u4e0a\u9762\u5f97\u4ee3\u7801\u8bf4\u660e\u4e86\uff0c\u53d8\u91cfx\u5728\u6574\u4e2arain\u51fd\u6570\u4f53\u5185\u90fd\u53ef\u4ee5\u4f7f\u7528\uff0c\u5e76\u53ef\u4ee5\u91cd\u65b0\u8d4b\u503c\u3002\u7531\u4e8e\u8fd9\u6761\u89c4\u5219\uff0c\u4f1a\u4ea7\u751f\u201c\u532a\u5937\u6240\u601d\u201d\u7684\u7ed3\u679c\uff0c\u89c2\u5bdf\u4e0b\u9762\u7684\u4ee3\u7801\u3002<\/p>\n
 <\/p>\n
<script type="text\/javascript">\r\n    var x = 1;\r\n    function rain(){\r\n        alert( x );        \/\/\u5f39\u51fa 'undefined'\uff0c\u800c\u4e0d\u662f1\r\n        var x = 'rain-man';\r\n        alert( x );        \/\/\u5f39\u51fa 'rain-man'\r\n    }\r\n    rain();\r\n<\/script>\r\n<\/code><\/pre>\n
\u662f\u7531\u4e8e\u5728\u51fd\u6570rain\u5185\u5c40\u90e8\u53d8\u91cfx\u5728\u6574\u4e2a\u51fd\u6570\u4f53\u5185\u90fd\u6709\u5b9a\u4e49\uff08 var x= 'rain-man'\uff0c\u8fdb\u884c\u4e86\u58f0\u660e\uff09\uff0c\u6240\u4ee5\u5728\u6574\u4e2arain\u51fd\u6570\u4f53\u5185\u9690\u85cf\u4e86\u540c\u540d\u7684\u5168\u5c40\u53d8\u91cfx\u3002<\/p>\n
\u8fd9\u91cc\u4e4b\u6240\u4ee5\u4f1a\u5f39\u51fa'undefined'\u662f\u56e0\u4e3a\uff0c\u7b2c\u4e00\u4e2a\u6267\u884calert(x)\u65f6\uff0c\u5c40\u90e8\u53d8\u91cfx\u4ecd\u672a\u88ab\u521d\u59cb\u5316\u3002\u6240\u4ee5\u4e0a\u9762\u7684rain\u51fd\u6570\u7b49\u540c\u4e8e\u4e0b\u9762\u7684\u51fd\u6570\uff1a<\/p>\n
 <\/p>\n
function rain(){\r\n    var x;\r\n    alert( x );\r\n    x = 'rain-man';\r\n    alert( x );\r\n}\r\n<\/code><\/pre>\n
5\u3001\u672a\u4f7f\u7528var\u5173\u952e\u5b57\u5b9a\u4e49\u7684\u53d8\u91cf\u90fd\u662f\u5168\u5c40\u53d8\u91cf\u3002<\/strong><\/h3>\n
 <\/p>\n
<script type="text\/javascript">\r\n    function rain(){\r\n        x = 100;    \/\/\u58f0\u660e\u4e86\u5168\u5c40\u53d8\u91cfx\u5e76\u8fdb\u884c\u8d4b\u503c\r\n    }\r\n    rain();\r\n    alert( x );    \/\/\u4f1a\u5f39\u51fa100\r\n<\/script>\r\n<\/code><\/pre>\n
\u8fd9\u4e5f\u662fJavaScript\u65b0\u624b\u5e38\u89c1\u7684\u9519\u8bef\uff0c\u65e0\u610f\u4e4b\u4e2d\u7559\u4e0b\u7684\u8bb8\u591a\u5168\u5c40\u53d8\u91cf\u3002<\/p>\n
6\u3001\u5168\u5c40\u53d8\u91cf\u90fd\u662fwindow\u5bf9\u8c61\u7684\u5c5e\u6027<\/strong><\/h3>\n
<script type="text\/javascript">\r\n    var x = 100 ;\r\n    alert( window.x );\/\/\u5f39\u51fa100\r\n    alert(x);\r\n<\/script>\r\n<\/code><\/pre>\n
\u7b49\u540c\u4e8e\u4e0b\u9762\u7684\u4ee3\u7801<\/p>\n
<script type="text\/javascript">\r\n    window.x = 100;\r\n    alert( window.x );\r\n    alert(x)\r\n<\/script>\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
\u5728\u5b66\u4e60JavaScript\u7684\u53d8\u91cf\u4f5c\u7528\u57df\u4e4b\u524d\uff0c\u6211\u4eec\u5e94\u5f53\u660e\u786e\u51e0\u70b9\uff1a JavaScript\u7684\u53d8\u91cf\u4f5c\u7528\u57df\u662f\u57fa\u4e8e\u5176\u7279\u6709\u7684 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[109],"tags":[],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3248"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3248"}],"version-history":[{"count":1,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3248\/revisions"}],"predecessor-version":[{"id":3249,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/3248\/revisions\/3249"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3248"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3248"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3248"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}