{"id":6132,"date":"2020-05-08T19:46:14","date_gmt":"2020-05-08T11:46:14","guid":{"rendered":"https:\/\/www.lilichao.com\/?p=6132"},"modified":"2022-05-14T19:50:29","modified_gmt":"2022-05-14T11:50:29","slug":"%e6%89%a7%e8%a1%8c%e4%b8%8a%e4%b8%8b%e6%96%87%ef%bc%88execution-context-%ef%bc%89","status":"publish","type":"post","link":"https:\/\/lilichao.com\/?p=6132","title":{"rendered":"\u6267\u884c\u4e0a\u4e0b\u6587\uff08execution context \uff09"},"content":{"rendered":"\n<p>\u53d8\u91cf\u5bf9\u8c61\uff08ES\u6807\u51c6\u4e2d\u79f0\u4e3a\u8bcd\u6cd5\u73af\u5883\uff09\u7528\u4e8e\u5b58\u50a8JS\u4e2d\u7684\u53d8\u91cf\uff0c\u53d8\u91cf\u5bf9\u8c61\u6240\u5728\u7684\u4f4d\u7f6e\u6211\u6682\u4e14\u79f0\u5176\u4e3a\u4f5c\u7528\u57df\u3002\u4e8e\u662f\u6211\u4eec\u9047\u5230\u4e86\u4e00\u4e2a\u65b0\u7684\u95ee\u9898\uff0c\u53d8\u91cf\u5bf9\u8c61\u5b58\u53d8\u91cf\uff0c\u4f5c\u7528\u57df\u5b58\u50a8\u53d8\u91cf\u5bf9\u8c61\u3002\u8c01\u53c8\u6765\u5b58\u50a8\u4f5c\u7528\u57df\u5462\uff1f<\/p>\n\n\n\n<p>\u5728JS\u4e2d\u8fd8\u5b58\u5728\u4e00\u4e2a\u4e1c\u897f\u53eb\u505a\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u6bcf\u4e00\u4e2a\u51fd\u6570\uff08\u5305\u62ec\u5168\u5c40\u4f5c\u7528\u57df\uff09\u90fd\u4f1a\u6709\u5176\u5bf9\u5e94\u7684\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587\u3002\u6267\u884c\u4e0a\u4e0b\u6587\u5728\u51fd\u6570\u5b9a\u4e49\u65f6\u5c31\u5df2\u521b\u5efa\uff0c\u51fd\u6570\u6267\u884c\u65f6\u6240\u9700\u7684\u4e00\u5207\u5305\u62ec\u4f5c\u7528\u57df\u94fe\u90fd\u5b58\u50a8\u5728\u6267\u884c\u4e0a\u4e0b\u6587\u4e2d\u3002\u6267\u884c\u4e0a\u4e0b\u6587\u4e2d\u5b58\u50a8\u7684\u4e1c\u897f\u5f88\u591a\u4e5f\u5f88\u6742\uff0c\u4e0d\u9700\u8981\u4e00\u4e00\u5217\u4e3e\uff0c\u4f60\u9700\u8981\u77e5\u9053\u7684\u5c31\u662f\u6267\u884c\u4e0a\u4e0b\u6587\u4e2d\u5305\u62ec\u51fd\u6570\u6267\u884c\u6240\u9700\u7684\u4e00\u5207\u4e1c\u897f\u3002<\/p>\n\n\n\n<p>\u6bcf\u4e00\u4e2a\u51fd\u6570\u90fd\u4f1a\u6709\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u6267\u884c\u4e0a\u4e0b\u6587\u53ea\u6709\u5728\u51fd\u6570\u6267\u884c\u65f6\u624d\u4f1a\u8d77\u4f5c\u7528\u3002\u5728JS\u4e2d\u8fd8\u5b58\u5728\u4e00\u4e2a\u53eb\u505a\u8c03\u7528\u6808\u7684\u5730\u65b9\uff0c\u8c03\u7528\u6808\u4e13\u95e8\u7528\u6765\u5b58\u50a8\u6b63\u5728\u6267\u884c\u7684\u51fd\u6570\u7684\u6267\u884c\u4e0a\u4e0b\u6587\u3002<\/p>\n\n\n\n<p>\u6808\uff08stack\uff09\uff0c\u6240\u8c13\u7684\u6808\u662f\u4e00\u79cd\u6570\u636e\u7ed3\u6784\u3002\u8fd9\u79cd\u7ed3\u6784\u7c7b\u4f3c\u4e8e\u67aa\u7684\u5f39\u5323\u3002<\/p>\n\n\n\n<p>\u5728\u5f39\u5323\u4e2d\uff0c\u5148\u538b\u5165\u7684\u5b50\u5f39\u4f1a\u5728\u5f39\u5323\u7684\u6700\u5e95\u90e8\uff0c\u6700\u540e\u538b\u5165\u7684\u5b50\u5f39\u5728\u5f39\u5323\u7684\u6700\u4e0a\u8fb9\u3002\u5f00\u67aa\u65f6\u6700\u540e\u538b\u5165\u7684\u5b50\u5f39\u6700\u5148\u53d1\u5c04\uff0c\u6700\u5148\u62bc\u5165\u7684\u5b50\u5f39\u6700\u540e\u53d1\u5c04\u3002<\/p>\n\n\n\n<p>\u8ba1\u7b97\u673a\u4e2d\u6808\u4e5f\u662f\u5982\u6b64\uff0c\u6700\u5148\u5b58\u5165\u7684\u6570\u636e\u4f1a\u5728\u6808\u7684\u6700\u4e0b\u8fb9\uff0c\u6808\u6700\u4e0b\u8fb9\u7684\u5bf9\u8c61\u79f0\u4e3a\u6808\u5e95\u5bf9\u8c61\u3002\u6700\u540e\u5b58\u5165\u7684\u6570\u636e\u4f1a\u5728\u6808\u7684\u6700\u4e0a\u8fb9\uff0c\u6808\u6700\u4e0a\u8fb9\u7684\u5bf9\u8c61\u88ab\u79f0\u4e3a\u6808\u9876\u5bf9\u8c61\u3002\u83b7\u53d6\u6570\u636e\u65f6\uff0c\u4f1a\u5148\u83b7\u53d6\u540e\u5b58\u5165\u7684\u5bf9\u8c61\uff0c\u4e5f\u5c31\u662f\u6808\u9876\u5bf9\u8c61\uff0c\u6700\u5148\u5b58\u5165\u7684\u5bf9\u8c61\u6700\u540e\u624d\u83b7\u53d6\u3002<\/p>\n\n\n\n<p>\u8c03\u7528\u6808\u5c31\u662f\u4e00\u4e2a\u5b58\u50a8\u6267\u884c\u4e0a\u4e0b\u6587\u7684\u6808\u3002\u8c03\u7528\u6808\u4f1a\u5728JS\u52a0\u8f7d\u65f6\u5c31\u4f1a\u521b\u5efa\uff0c\u521b\u5efa\u540e\u4f1a\u5c06\u5168\u5c40\u4f5c\u7528\u57df\u7684\u6267\u884c\u4e0a\u4e0b\u6587\u653e\u5165\u6dfb\u52a0\u8fd1\u8c03\u7528\u6808\uff0c\u4e5f\u5c31\u662f\u8bf4\u8c03\u7528\u6808\u4e2d\u7684\u6808\u5e95\u5bf9\u8c61\u662f\u5168\u5c40\u4f5c\u7528\u57df\u7684\u6267\u884c\u4e0a\u4e0b\u6587\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e00\u70b9\u53ef\u4ee5\u901a\u8fc7\u5f00\u53d1\u8fd9\u5de5\u5177\u67e5\u770b\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"680\" height=\"479\" src=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194758436.png\" alt=\"\" class=\"wp-image-6134\" srcset=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194758436.png 680w, https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194758436-300x211.png 300w\" sizes=\"(max-width: 680px) 100vw, 680px\" \/><figcaption>\u8c03\u7528\u6808<\/figcaption><\/figure><\/div>\n\n\n\n<p>\u901a\u8fc7\u5f00\u53d1\u8005\u5de5\u5177\u53f3\u4fa7\u7684Call Stack\u5c31\u53ef\u4ee5\u770b\u5230\u5f53\u524d\u4ee3\u7801\u7684\u8c03\u7528\u6808\u3002\u73b0\u5728\u4ee3\u7801\u505c\u5728\u4e8614\u884c\uff0c\u4f4d\u4e8e\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u6240\u4ee5\u8c03\u7528\u6808\u4e2d\u53ea\u5b58\u5728\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587(anonymous)\uff0canonymous\u610f\u4e3a\u533f\u540d\u7684\uff0c\u5728\u8fd9\u91cc\u5b9e\u9645\u4e0a\u6307\u7684\u5c31\u662f\u5168\u5c40\u6267\u884c\u4e0a\u4e0b\u6587\u3002\u73b0\u5728\u8c03\u7528\u6808\u4e2d\u53ea\u6709\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u6240\u4ee5\u5b83\u5373\u4f7f\u6808\u5e95\u5bf9\u8c61\u53c8\u662f\u6808\u9876\u5bf9\u8c61\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p>\u7b80\u5355\u8bf4\u6765\uff0c\u6808\u9876\u5bf9\u8c61\u8868\u793a\u7684\u662f\u5f53\u524d\u6b63\u5728\u6267\u884c\u7684\u51fd\u6570\u3002\u6240\u4ee5\u73b0\u5728\u6808\u9876\u5bf9\u8c61\u662f\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u610f\u5473\u7740\u5f53\u524d\u6b63\u5728\u6267\u884c\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\u7684\u4ee3\u7801\u3002\u5b83\u4e0b\u8fb9\u7684Scope\u663e\u793a\u7684\u5c31\u662f\u5f53\u524d\u4e0a\u4e0b\u6587\u4e2d\u5b58\u50a8\u7684\u4f5c\u7528\u57df\u94fe\u3002<\/p>\n\n\n\n<p>\u73b0\u5728\u8c03\u7528\u4e00\u4e2a\u51fd\u6570\uff0c\u518d\u6765\u89c2\u5bdf\u8c03\u7528\u6808\u6709\u4f55\u53d8\u5316\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"655\" height=\"354\" src=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194805615.png\" alt=\"\" class=\"wp-image-6135\" srcset=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194805615.png 655w, https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194805615-300x162.png 300w\" sizes=\"(max-width: 655px) 100vw, 655px\" \/><figcaption>\u8c03\u7528\u6808<\/figcaption><\/figure><\/div>\n\n\n\n<p>\u73b0\u5728\u5c06\u4ee3\u7801\u505c\u5728\u7b2c9\u884c\uff0c\u4e5f\u5c31\u662fouter\u51fd\u6570\u5f00\u59cb\u6267\u884c\u3002\u6b64\u65f6\u4f60\u4f1a\u53d1\u73b0\u8c03\u7528\u6808\u4e2d\u591a\u51fa\u6765\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587outer\uff0c\u6b64\u65f6\u6267\u884c\u6808\u7684\u6808\u9876\u5b58\u653e\u7684\u662fouter\u7684\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u8fd9\u610f\u5473\u8fd9\u73b0\u5728JS\u89e3\u6790\u5668\uff08\u6d4f\u89c8\u5668\uff09\u6b63\u5728\u6267\u884couter\u51fd\u6570\uff0c\u540c\u65f6Scope\u4e5f\u5207\u6362\u4e3aouter\u51fd\u6570\u7684\u4f5c\u7528\u57df\u94fe\u3002<\/p>\n\n\n\n<p>\u5f53\u65ad\u70b9\u6253\u5728\u5185\u90e8\u51fd\u6570\u65f6\uff0c\u8c03\u7528\u6808\u53c8\u4f1a\u53d1\u751f\u65b0\u7684\u53d8\u5316\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"712\" height=\"331\" src=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194811762.png\" alt=\"\" class=\"wp-image-6136\" srcset=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194811762.png 712w, https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/05\/20220514194811762-300x139.png 300w\" sizes=\"(max-width: 712px) 100vw, 712px\" \/><figcaption>\u8c03\u7528\u6808<\/figcaption><\/figure><\/div>\n\n\n\n<p>\u73b0\u5728\u65ad\u70b9\u6253\u5230\u4e86\u5185\u90e8\u51fd\u6570\u4e2d\uff0c\u4ee3\u7801\u505c\u5728\u4e8611\u884c\u3002\u5728\u8c03\u7528\u6808\u4e2d\u53c8\u591a\u51fa\u4e86\u4e00\u4e2a\u533f\u540d\u7684\u8c03\u7528\u6808\uff0c\u4e4b\u6240\u4ee5\u663e\u793a\u533f\u540d\u662f\u56e0\u4e3a\u5185\u90e8\u51fd\u6570\u6ca1\u6709\u8d77\u540d\u5b57\u3002<\/p>\n\n\n\n<p>\u5728\u8c03\u7528\u6808\u4e2d\uff0couter\u7684\u4e0a\u4e0b\u6587\u5df2\u7ecf\u6d88\u5931\uff0c\u8fd9\u662f\u56e0\u4e3aouter\u6267\u884c\u5b8c\u6bd5\uff0c\u6267\u884c\u5b8c\u6bd5\u7684\u51fd\u6570\u4e0a\u4e0b\u6587\u4f1a\u81ea\u52a8\u4ece\u8c03\u7528\u6808\u4e2d\u5f39\u51fa\u3002\u73b0\u5728\u7684\u6808\u9876\u7684\u4e0a\u4e0b\u6587\u662f\u5185\u90e8\u533f\u540d\u51fd\u6570\u7684\u4e0a\u4e0b\u6587\uff0c\u540c\u65f6\u4f60\u4f1a\u53d1\u73b0\u5b83\u7684Scope\u4e5f\u53d8\u6210\u4e86\u5185\u90e8\u51fd\u6570\u7684\u4f5c\u7528\u57df\u94fe\u3002<\/p>\n\n\n\n<p>\u4e4b\u6240\u4ee5\u5185\u90e8\u51fd\u6570\u53ef\u4ee5\u8bbf\u95ee\u5230\u5916\u90e8\u51fd\u6570\u4e2d\u7684\u53d8\u91cf\u548c\u53c2\u6570\uff0c\u5176\u5b9e\u539f\u56e0\u5f88\u7b80\u5355\uff0c\u56e0\u4e3a\u6267\u884c\u53d8\u91cf\u548c\u53c2\u6570\u65e9\u5c31\u5b58\u50a8\u5230\u4e86\u5185\u90e8\u51fd\u6570\u7684\u6267\u884c\u4e0a\u4e0b\u6587\u4e2d\uff0c\u8c03\u7528\u5185\u90e8\u51fd\u6570\u65f6\uff0c\u5176\u4e0a\u4e0b\u6587\u88ab\u81ea\u52a8\u52a0\u8f7d\uff0c\u4e0e\u6b64\u540c\u65f6\u5176\u4e2d\u5b58\u50a8\u7684\u4f5c\u7528\u57df\u94fe\u4e5f\u88ab\u627e\u5230\uff0c\u7531\u6b64\u4fbf\u6709\u4e86\u95ed\u5305\u3002<\/p>\n\n\n\n<p>\u5173\u4e8e\u6267\u884c\u4e0a\u4e0b\u6587\uff0c\u6211\u4eec\u53ef\u4ee5\u6682\u4e14\u5148\u4e86\u89e3\u5230\u8fd9\u6837\u4e00\u4e2a\u7a0b\u5ea6\uff0c\u4e0b\u8fb9\u6211\u505a\u4e00\u4e2a\u7b80\u5355\u7684\u603b\u7ed3\uff1a<\/p>\n\n\n\n<ol><li>\u6bcf\u4e00\u4e2a\u51fd\u6570\uff08\u5305\u62ec\u5168\u5c40\u4f5c\u7528\u57df\uff09\u90fd\u6709\u4e00\u4e2a\u6267\u884c\u4e0a\u4e0b\u6587<\/li><li>\u6267\u884c\u4e0a\u4e0b\u6587\u4e2d\u5b58\u50a8\u4e86\u5f53\u524d\u51fd\u6570\u6267\u884c\u6240\u9700\u7684\u4e00\u5207\u5185\u5bb9\uff08\u5305\u62ec\u4f5c\u7528\u57df\u94fe\uff09<\/li><li>\u8c03\u7528\u6808\u7528\u6765\u5b58\u50a8\u5f53\u524d\u6b63\u5728\u6267\u884c\u6216\u7b49\u5f85\u6267\u884c\u7684\u51fd\u6570\u7684\u6267\u884c\u4e0a\u4e0b\u6587<\/li><li>\u8c03\u7528\u6808\u7684\u6808\u9876\u5bf9\u8c61\u8868\u793a\u5f53\u524d\u6b63\u5728\u6267\u884c\u7684\u51fd\u6570\u7684\u6267\u884c\u4e0a\u4e0b\u6587<\/li><li>\u6267\u884c\u5b8c\u6bd5\u6267\u884c\u4e0a\u4e0b\u6587\u4f1a\u4ece\u6808\u9876\u5f39\u51fa\uff0c\u7136\u540e\u7ee7\u7eed\u6267\u884c\u4e0b\u4e00\u4e2a\u51fd\u6570<\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u53d8\u91cf\u5bf9\u8c61\uff08ES\u6807\u51c6\u4e2d\u79f0\u4e3a\u8bcd\u6cd5\u73af\u5883\uff09\u7528\u4e8e\u5b58\u50a8JS\u4e2d\u7684\u53d8\u91cf\uff0c\u53d8\u91cf\u5bf9\u8c61\u6240\u5728\u7684\u4f4d\u7f6e\u6211\u6682\u4e14\u79f0\u5176\u4e3a\u4f5c\u7528\u57df\u3002\u4e8e\u662f\u6211\u4eec\u9047\u5230\u4e86\u4e00 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6045,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[241],"tags":[200,234,252],"_links":{"self":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6132"}],"collection":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6132"}],"version-history":[{"count":2,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6132\/revisions"}],"predecessor-version":[{"id":6137,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6132\/revisions\/6137"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/media\/6045"}],"wp:attachment":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}