{"id":2139,"date":"2019-03-22T11:04:00","date_gmt":"2019-03-22T03:04:00","guid":{"rendered":"http:\/\/www.imzouyang.com\/blog\/?p=2139"},"modified":"2020-10-28T22:46:47","modified_gmt":"2020-10-28T14:46:47","slug":"js%e5%8e%9f%e7%90%86%ef%bc%9a%e7%8b%ac%e7%89%b9%e7%9a%84js%e5%8f%98%e9%87%8f","status":"publish","type":"post","link":"http:\/\/www.imzouyang.com\/blog\/archives\/2139.html","title":{"rendered":"js\u539f\u7406\uff1a\u72ec\u7279\u7684js\u53d8\u91cf"},"content":{"rendered":"\n

\u672c\u6587\u4ece\u6211\u7684\u7b14\u8bb0\u6c47\u603b\u53d8\u91cf\u7684\u4e00\u4e9b\u6bd4\u8f83\u7279\u522b\u7684\u7279\u6027\u8bf4\u660e\u5982\u4e0b<\/p>\n\n\n\n

<\/p>\n\n\n\n

1\u3001\u53d8\u91cf\u7533\u660e\u7684\u63d0\u5347<\/strong><\/p>\n\n\n\n

\u6211\u6709\u4e00\u7bc7\u6587\u7ae0\u8bb2\u4e86\u8fd9\u4e2a\uff1aLink<\/a><\/p>\n\n\n\n

2\u3001<\/strong>\u58f0\u660e\u53d8\u91cf var a = 10; \u00a0\u90a3\u4e48\u4e0d\u8981var\uff0c\u5176\u5b9e\u4e5f\u80fd\u58f0\u660e\u4e00\u4e2a\u53d8\u91cf\uff0c\u5e76\u4e0d\u4f1a\u62a5\u9519 \u3002a=10; \u8fd9\u4e2a\u53d8\u91cf\u4f1a\u662f\u5168\u5c40\u7684\uff0c\u4e0d\u8bba\u8fd9\u4e2aa\u662f\u5426\u5728\u4e00\u4e2a\u51fd\u6570\u5185\u58f0\u660e\uff0c\u8fd8\u662f\u5728\u54ea\u58f0\u660e\u3002
\u603b\u7ed3\u5c31\u662f\uff0c\u5728\u4efb\u4f55\u5730\u65b9\u9690\u5f0f\u5b9a\u4e49\u7684\u53d8\u91cf\u90fd\u4f1a\u5b9a\u4e49\u5728\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\uff0c\u5373\u4e0d\u901a\u8fc7 var \u58f0\u660e\u76f4\u63a5\u8d4b\u503c\u7684\u53d8\u91cf\u3002\u4e0d\u5efa\u8bae\u8fd9\u79cd\u4e66\u5199\u65b9\u5f0f\u3002<\/p>\n\n\n\n

\/\/\u5f53\u7528a=10,\u5199\u5728\u51fd\u6570\u5185\u90e8\u65f6\uff0c\u8fd9\u4e2aa\u4f1a\u88abjs\u5b9a\u4e49\u4e3a\u5168\u5c40\u53d8\u91cf:\nfunction aaa(){\n a=10;\n var b=20;\n}     \naaa();\nalert(a);\/\/\u8fd4\u56de10\uff0c\u662f\u53ef\u4ee5alert\u5230\u51fd\u6570\u5185\u90e8\u7684a\u7684\nalert(b);\/\/\u62a5\u9519undefined\n\n\/\/\u793a\u4f8b2\nvar a,b;\nvar c,d;\nfunction box(){var a=b=3;} \/\/\u76f8\u5f53\u4e8evar a=b   b=3;    b\u662f\u5168\u5c40\u7684\uff0ca\u662f\u5c40\u90e8\u7684\nbox();\nc=d=4; \/\/\u76f8\u5f53\u4e8evar c=d   d=4;    c\u3001d\u5728window\u4f5c\u7528\u57df\u4e0b\uff0c\u90fd\u662f\u5168\u5c40\u7684\nalert(a); \/\/\u8fd4\u56deundefined\nalert(b); \/\/\u8fd4\u56de3\nalert(c); \/\/\u8fd4\u56de4\nalert(d); \/\/\u8fd4\u56de4<\/code><\/pre>\n\n\n\n
<\/p>\n\n\n\n
3\u3001\u53d8\u91cf\u7684\u67e5\u627e\uff1a<\/strong>\u662f\u53bb\u5bfb\u627e\u6700\u8fd1\u7684var\u58f0\u660e\u7684\u90a3\u4e2a\uff0c\u627e\u4e0d\u5230\u5c31\u518d\u53bb\u5916\u4e00\u5c42\u627e\uff0c\u627e\u4e0d\u5230\u5c31\u518d\u53bb\u5916\u4e00\u5c42\u2026\u2026<\/p>\n\n\n\n
\/\/\u793a\u4f8b1\uff1a\nvar a = 10;\nfunction aaa(){ alert(a);}\naaa();   \/\/\u8fd4\u56de10\n\n\/\/\u793a\u4f8b2\uff1a\nvar a = 10;\nfunction aaa(){\n alert(a);\n var a =20;\n}\naaa();   \/\/\u8fd4\u56deundefined\n\/\/\u4e0a\u9762\u8fd9\u4e2a\u4f8b\u5b50 aaa\u51fd\u6570 \u5185\u90e8\u7a0b\u5e8f\u4f1a\u6709\u4e00\u4e2a\u9884\u89e3\u6790,\u76f8\u5f53\u4e8e\u53d8\u6210\u4e86 var a;alert(a); a =20;\n\n\/\/\u793a\u4f8b3\uff1a\nvar a = 10;\nfunction aaa(){\n var a =20;\n alert(a);\n}\naaa();   \/\/\u8fd4\u56de20\n\n\n\/\/\u793a\u4f8b4\uff1a\nvar a = 10;\nfunction aaa(){ \n a =20; \n alert(a); \n}\naaa();   \/\/\u8fd4\u56de20   \u6ce8\u610f\u987a\u5e8f\uff0c\u5b83\u662f\u5148\u627e\u5230\u5916\u5c42a=10,\u7136\u540e\u51fd\u6570\u5185\u90e8\u66f4\u6539\u4e3a\u4e8620\n\n\/\/\u793a\u4f8b5\uff1a\nvar a = 10;\nfunction aaa(){  \n alert(a);\n a =20; \n}\naaa();   \/\/\u8fd4\u56de10<\/code><\/pre>\n\n\n\n
4\u3001\u5f53\u53c2\u6570\u8ddf\u5c40\u90e8\u53d8\u91cf\u91cd\u540d\u65f6\uff0c\u4f18\u5148\u7ea7\u662f\u76f8\u7b49\u7684\u3002<\/strong><\/p>\n\n\n\n
var a = 10;\nfunction aaa(a){\n alert(a); \n var a =20;\n}\naaa(a);   \/\/\u8fd4\u56de10<\/code><\/pre>\n\n\n\n
5\u3001\u53d8\u91cf\u7684\u5206\u7ec4\u9009\u62e9\u7b26<\/strong><\/p>\n\n\n\n
var a = (1,2,3)    \nalert(a);   \/\/\u8fd4\u56de\u7684\u662f3   <\/code><\/pre>\n\n\n\n
\u8fd9\u79cd\u5206\u7ec4\u5199\u6cd5\uff0c\u4f1a\u8d4b\u7ed9\u6700\u540e\u4e00\u4e2a\u3002<\/p>\n\n\n\n
6\u3001<\/strong>\u5176\u5b83\u53d8\u91cf\u7684\u57fa\u7840\u77e5\u8bc6\u4e0d\u662f\u672c\u6587\u91cd\u70b9\uff1a\u57fa\u672c\u7c7b\u578b\u7684\u8d4b\u503c\uff0c\u5f15\u7528\u7c7b\u578b\u7684\u8d4b\u503c\uff0c\u6ca1\u6709\u5b9a\u4e49\u7684\u53d8\u91cf\u4f1a\u600e\u6837\uff0c\u8fd9\u4e9b\u7565\u3002<\/p>\n\n\n\n
\uff08\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"
\u672c\u6587\u4ece\u6211\u7684\u7b14\u8bb0\u6c47\u603b\u53d8\u91cf\u7684\u4e00\u4e9b\u6bd4\u8f83\u7279\u522b\u7684\u7279\u6027\u8bf4\u660e\u5982\u4e0b 1\u3001\u53d8\u91cf\u7533\u660e\u7684\u63d0\u5347 \u6211\u6709\u4e00\u7bc7\u6587\u7ae0\u8bb2\u4e86\u8fd9\u4e2a\uff1aLink 2\u3001\u58f0 … \u7ee7\u7eed\u9605\u8bfb js\u539f\u7406\uff1a\u72ec\u7279\u7684js\u53d8\u91cf<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"aside","meta":[],"categories":[30],"tags":[],"_links":{"self":[{"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/posts\/2139"}],"collection":[{"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/comments?post=2139"}],"version-history":[{"count":2,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/posts\/2139\/revisions"}],"predecessor-version":[{"id":2143,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/posts\/2139\/revisions\/2143"}],"wp:attachment":[{"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/media?parent=2139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/categories?post=2139"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.imzouyang.com\/blog\/wp-json\/wp\/v2\/tags?post=2139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}