{"id":203900,"date":"2020-11-25T04:07:12","date_gmt":"2020-11-24T20:07:12","guid":{"rendered":"http:\/\/4563.org\/?p=203900"},"modified":"2020-11-25T04:07:12","modified_gmt":"2020-11-24T20:07:12","slug":"%e5%85%b3%e4%ba%8e-javascript-%e7%9a%84%e5%8f%98%e9%87%8f%e5%ae%9a%e4%b9%89%e4%b8%80%e7%82%b9%e7%96%91%e6%83%91%ef%bc%8c%e6%b1%82%e5%90%84%e4%bd%8d%e5%a4%a7%e4%bd%ac%e6%8c%87%e5%af%bc","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=203900","title":{"rendered":"\u5173\u4e8e Javascript \u7684\u53d8\u91cf\u5b9a\u4e49\u4e00\u70b9\u7591\u60d1\uff0c\u6c42\u5404\u4f4d\u5927\u4f6c\u6307\u5bfc"},"content":{"rendered":"
\n
\n
\n

\u5173\u4e8e Javascript \u7684\u53d8\u91cf\u5b9a\u4e49\u4e00\u70b9\u7591\u60d1\uff0c\u6c42\u5404\u4f4d\u5927\u4f6c\u6307\u5bfc <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : wymanAtV2 <\/span> <\/i> 1<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
js \u91cc\u9762\u76f4\u63a5\u8bbf\u95ee\u4e00\u4e2a\u672a\u58f0\u660e\u7684\u53d8\u91cf\u662f\u4f1a\u62a5\u9519\u201cxxx is not defined\u201d\u7684\uff0c\u4f46\u662f\u5f53\u6211\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u6216\u8005\u76f4\u63a5\u4f7f\u7528\u5bbf\u4e3b\u5bf9\u8c61\u65f6\uff0c\u4f8b\u5982\u6d4f\u89c8\u5668\u73af\u5883\u4e0b window.variable,\u662f\u4f1a\u8fd4\u56de\u4e00\u4e2a undefined \u7684\uff0c\u8fd9\u4e00\u70b9\u6709\u70b9\u7591\u60d1\uff0c\u8fd9\u548c undefined \u7684\u5b9a\u4e49\u4e0d\u662f\u6709\u51b2\u7a81\u5417\uff0cvariable \u8fd8\u6ca1\u58f0\u660e\u554a\uff1f
\u6c42\u5404\u4f4d\u6307\u6559 <\/div>\n
\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (10<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : wyongjian <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u540e\u8005\u7684 undefined \u53ea\u662f\u8bf4\u660e\u6ca1\u6709\u8fd4\u56de\u503c\u5427 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : wymanAtV2 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @wyongjian \u55ef\u55ef\uff0c\u8fd9\u4e2a\u60a8\u542f\u53d1\u4e86\u6211\uff0c\u4e0d\u8fc7\u6211\u8fd8\u662f\u4e0d\u592a\u80fd\u7406\u89e3\u4e24\u8005\u5728\u4f7f\u7528\u7684\u8868\u73b0\u4e0a\u7684\u4e0d\u540c\uff0c\u4f8b\u5982\u6709\u4e00\u4e2a\u51fd\u6570\u9700\u8981\u4e00\u4e2a\u53c2\u6570\uff0c\u6211\u4f20\u9012\u53c2\u6570\u7684\u65f6\u5019 func(a,),\u6b64\u65f6\u6211\u4f20\u5165\u4e00\u4e2a\u672a\u5b9a\u4e49\u7684\u53d8\u91cf variable\uff0c\u80af\u5b9a\u662f\u4f1a\u62a5\u9519\u7684\uff1b\u4f46\u662f\u6211\u4f20\u5165\u4e00\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u4ed6\u662f\u4f1a\u9ed8\u8ba4\u4f20\u5165\u4e00\u4e2a undefined \u7684\uff1b <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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    \u8cc7\u6df1\u5927\u4f6c : xiongotom <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    undefined \u4e0d\u5c31\u662f\u672a\u58f0\u660e\u561b\uff0c\u7b26\u5408\u5b9a\u4e49\u554a\u3002\u53ef\u80fd\u4f60\u7684\u7591\u60d1\u65f6\u4e3a\u5565\u76f4\u63a5\u8bbf\u95ee\u4f1a\u62a5\u9519\uff0c\u76f4\u63a5\u4f7f\u7528\u53d8\u91cf\u7684\u65f6\u5019\u662f\u4e0d\u4f1a\u5728 window \u4e0a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u53d8\u91cf\u7684\uff1b\u4f46\u6bd4\u5982 a = 10 \u8fd9\u6837\u5b50\uff0c\u662f\u4f1a\u5728 window \u4e0a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u53d8\u91cf\uff0c\u539f\u56e0\u662f\u6709\u4e2a LHS \u548c RHS \u7684\u533a\u522b\uff0c\u7b80\u5355\u7406\u89e3\u5c31\u662f\u5728\u8d4b\u503c\u64cd\u4f5c\u7b26\u7684\u5de6\u8fb9\u5c31\u4f1a\u81ea\u52a8\u521b\u5efa\uff0c\u53f3\u8fb9\u5219\u4e0d\u4f1a\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : wymanAtV2 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @xiongotom \u55ef\u55ef\uff0c\u9996\u5148\u611f\u8c22\u60a8\u7684\u89e3\u60d1\uff0c\u60a8\u7684\u89e3\u91ca\u6211\u662f\u7406\u89e3\u7684\uff1b\u6211\u7591\u60d1\u7684\u70b9\u5728\u4e8e\u540e\u8005\uff0c\u4e3a\u4ec0\u4e48\u76f4\u63a5\u8bbf\u95ee\u4e00\u4e2a\u5bf9\u8c61\u91cc\u7684\u5c5e\u6027\u5c31\u4e0d\u4f1a\u6709\u62a5\u9519\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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    \u8cc7\u6df1\u5927\u4f6c : zzzzzzggggggg <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    undefined \u4f1a\u5728\u4ee5\u4e0b\u51e0\u79cd\u60c5\u51b5\u8fd4\u56de\uff1a
    1. \u6ca1\u6709\u8fd4\u56de\u8bed\u53e5\u7684\u51fd\u6570\u8fd0\u884c\u7ed3\u675f\uff0c\u5c31\u4f1a\u8fd4\u56de undefined
    2. \u8bbf\u95ee\u6570\u7ec4\u4e2d\u4e0d\u5b58\u5728\u7684\u4e0b\u6807\u548c\u5bf9\u8c61\u4e0d\u5b58\u5728\u7684\u5c5e\u6027
    3. void \u8fd0\u7b97\u7b26\u4f1a\u8fd4\u56de undefined<\/p>\n

    \u5176\u4ed6\u7684\u60c5\u51b5\u6309\u7167\u4f60\u7406\u89e3\u7684\u8fd4\u56de\u5373\u53ef <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : wymanAtV2 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @zzzzzzggggggg <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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    \u8cc7\u6df1\u5927\u4f6c : marcong95 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @wymanAtV2 #4 \u56e0\u4e3a window.a \u8fd9\u79cd\u7528\u6cd5\u65e2\u53ef\u4ee5\u4f5c\u4e3a LHS \u53c8\u53ef\u4ee5\u4f5c\u4e3a RHS \uff1f\u6216\u8005\u8bf4 window \u672c\u8eab\u5c31\u662f\u4e00\u4e2a\u5df2\u7ecf\u5b9a\u4e49\u7684\u53d8\u91cf\uff0cwindow.a \u53ea\u662f\u5bf9\u5df2\u5b9a\u4e49\u7684\u53d8\u91cf\u6307\u5411\u7684\u5bf9\u8c61\u7684\u4e00\u4e2a\u5c5e\u6027 a \u8fdb\u884c\u64cd\u4f5c\uff0c\u800c\u8fd9\u79cd\u64cd\u4f5c\u5e76\u4e0d\u662f\u5bf9\u672a\u5b9a\u4e49\u53d8\u91cf\u7684\u64cd\u4f5c\uff0c\u6240\u4ee5\u4e0d\u4f1a\u4ea7\u751f\u9519\u8bef\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xiongotom <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @marcong95 \u662f\u7684\u3002js \u4e2d\u7684\u5b9a\u4e49\u5c31\u662f\u8fd9\u6837\uff0c\u5982\u679c\u65b9\u6cd5\u6216\u8005\u8bed\u53e5\u4e2d\u64cd\u4f5c\u7684\u53d8\u91cf\u6ca1\u6709\u8d4b\u503c\uff0c\u5c31\u4f1a\u8fd4\u56de undefined \uff1b\u76f4\u63a5\u4f7f\u7528\u53d8\u91cf\u4f1a\u62a5\u9519\u662f\u56e0\u4e3a js \u5f15\u64ce\u4e00\u76f4\u627e\u5230 window \u90fd\u627e\u4e0d\u5230\u8fd9\u4e2a\u53d8\u91cf\u3002\u800c\u7528 window.a \u7684\u8bdd\uff0c\u5c31\u662f\u524d\u9762\u90a3\u4e00\u6761\u89c4\u5219\uff0cjs \u53d8\u91cf\u4e0a\u7684\u5c5e\u6027\u672c\u5c31\u65e0\u9700\u7279\u5730\u7684\u53bb\u58f0\u660e\u4e00\u4e0b\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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    \u8cc7\u6df1\u5927\u4f6c : yzqtdu <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8fd8\u6709\u4e00\u70b9\u5f88\u591a\u4eba\u6ca1\u63d0\u5230\u7684\u662f\uff0cJS \u91cc\u7684\u5bf9\u8c61\u5341\u5206\u7075\u6d3b\uff0c\u53ef\u4ee5\u52a8\u6001\u6dfb\u52a0\u3001\u5220\u9664\u5c5e\u6027\uff0c\u56e0\u6b64\u8bbe\u8ba1\u7684\u65f6\u5019\u5141\u8bb8\u8bbf\u95ee\u672a\u5b9a\u4e49\u5c5e\u6027\u53ef\u4ee5\u907f\u514d\u4e00\u4e9b\u4e0d\u5fc5\u8981\u7684\u9ebb\u70e6\uff0c\u4f8b\u5982\u6839\u636e\u6761\u4ef6\u6dfb\u52a0\u67d0\u4e2a\u5c5e\u6027\uff0c\u5982\u679c\u6761\u4ef6\u4e0d\u6210\u7acb\u672a\u7ed1\u5b9a\u5219\u540e\u9762\u7684\u8bbf\u95ee\u62a5\u9519\uff0c\u6210\u7acb\u5219\u987a\u5229\u8fd0\u884c\uff0c\u8fd9\u6837\u6240\u6709\u5bf9\u8be5\u5c5e\u6027\u7684\u8bbf\u95ee\u90fd\u8981\u52a0\u4e0a\u662f\u5426\u5b58\u5728\u7684\u5224\u65ad\uff0cif (prop in obj && typeof obj[prop] == “function”) obj[prop]() <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : wymanAtV2 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u611f\u8c22\u5404\u4f4d\u7684\u6307\u70b9 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"

    \u5173\u4e8e Javascript \u7684\u53d8\u91cf…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/203900"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=203900"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/203900\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=203900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=203900"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=203900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}