{"id":6046,"date":"2020-04-28T19:10:24","date_gmt":"2020-04-28T11:10:24","guid":{"rendered":"https:\/\/www.lilichao.com\/?p=6046"},"modified":"2022-05-14T20:00:26","modified_gmt":"2022-05-14T12:00:26","slug":"%e5%85%b6%e4%bb%96%e5%80%bc","status":"publish","type":"post","link":"https:\/\/lilichao.com\/?p=6046","title":{"rendered":"\u5176\u4ed6\u503c"},"content":{"rendered":"\n

\u6570\u5b57\u548c\u5b57\u7b26\u4e32\u662f\u6700\u6613\u4e8e\u7406\u89e3\u7684\u503c\u3002\u9664\u6b64\u4e4b\u5916\uff0cJS\u79cd\u8fd8\u6709\u51e0\u79cd\u503c\uff0c\u8fd9\u51e0\u79cd\u503c\u672c\u8eab\u6bd4\u8f83\u7b80\u5355\uff0c\u5c31\u653e\u5728\u4e00\u8d77\u8bf4\u4e86\u3002<\/p>\n\n\n\n

\u5e03\u5c14\u503c\uff08boolean\uff09<\/h2>\n\n\n\n

\u5e03\u5c14\u503c\u542c\u7740\u6bd4\u8f83\u5947\u602a\uff0c\u4f46\u662f\u5728\u73b0\u5b9e\u751f\u6d3b\u79cd\u4e5f\u4f1a\u4f7f\u7528\u5230\u3002\u6bd4\u5982\u8bf4\u6211\u4eec\u5728\u8c08\u8bba\u516b\u5366\u65f6\uff0c\u7ecf\u5e38\u4f1a\u8bf4\u5230\uff0c\u8fd9\u4e8b\u662f\u771f\u7684\u8fd8\u662f\u5047\u7684\uff1f\u771f\u548c\u5047\u5c31\u662f\u5e03\u5c14\u503c\u3002<\/p>\n\n\n\n

\u5e03\u5c14\u503c\u901a\u5e38\u4f1a\u7528\u4e8e\u903b\u8f91\u5224\u65ad\u3002\u5982\u679c\u8fd9\u4e8b\u662f\u771f\u7684\u6211\u5c31\u600e\u4e48\u600e\u4e48\u6837\uff0c\u5982\u679c\u662f\u5047\u7684\u5c31\u600e\u4e48\u600e\u4e48\u6837\u3002\u5e03\u5c14\u503c\u4e00\u5171\u6709\u4e24\u79cd\u503ctrue\u548cfalse\uff0ctrue\u8868\u793a\u771f\uff0cfalse\u8868\u793a\u5047\u3002<\/p>\n\n\n\n

let a = true\n\nlet b = false<\/code><\/pre>\n\n\n\n
\u7a7a\u503c\uff08null\uff09<\/h2>\n\n\n\n
\u7a7a\u503c\u7528\u6765\u8868\u793a\u6ca1\u6709\uff0c\u4e0d\u5b58\u5728\u3002\u8fd9\u79cd\u7c7b\u578b\u7684\u503c\u53ea\u6709\u4e00\u4e2a\u5c31\u662fnull\u3002\u7a0b\u5e8f\u79cd\u51e1\u662f\u7a7a\u7684\u3001\u6ca1\u6709\u7684\u3001\u4e0d\u5b58\u5728\u7684\u90fd\u53ef\u4ee5\u7528null\u8868\u793a\u3002<\/p>\n\n\n\n
let a = null<\/code><\/pre>\n\n\n\n
\u672a\u5b9a\u4e49\uff08undefined\uff09<\/h2>\n\n\n\n
\u672a\u5b9a\u4e49\u548c\u7a7a\u503c\u7c7b\u4f3c\uff0c\u4e5f\u53ef\u4ee5\u7406\u89e3\u4e3a\u7a7a\u7684\uff0c\u4e0d\u5b58\u5728\u7684\u3002\u8fd9\u79cd\u7c7b\u578b\u7684\u503c\u4e5f\u662f\u53ea\u6709\u4e00\u4e2aundefined\u3002undefined\u7684\u610f\u601d\u548cnull\u5f88\u50cf\uff0c\u4f7f\u7528\u573a\u666f\u4e5f\u51e0\u4e4e\u4e00\u81f4\uff0c\u5982\u679c\u8bf4\u8981\u533a\u5206\u7684\u8bdd\uff0c\u5bf9\u4e8e\u6211\u4eec\u6765\u8bb2\u8981\u8bbe\u7f6e\u7a7a\u7684\u3001\u4e0d\u5b58\u5728\u7684\u90fd\u4f1a\u4f7f\u7528null\u3002\u800cundefined\u90fd\u662f\u7531\u89e3\u6790\u5668\u81ea\u52a8\u8bbe\u7f6e\u7684\uff0c\u50cf\u4f7f\u7528var\u58f0\u660e\u4f46\u662f\u6ca1\u6709\u8d4b\u503c\u7684\u53d8\u91cf\u3001\u50cf\u662f\u6ca1\u6709\u8fd4\u56de\u503c\u7684\u51fd\u6570\u7b49\u90fd\u4f1a\u8fd4\u56deundefined\u3002\u4f60\u53ef\u80fd\u4f1a\u89c9\u5f97\u4e0d\u597d\u533a\u5206\uff0c\u53ef\u4ee5\u8fd9\u4e48\u8bb0\uff0c\u5f00\u53d1\u65f6\u6211\u4eec\u901a\u5e38\u4e0d\u4f1a\u4e3b\u52a8\u53bb\u8bbe\u7f6eundefined\u3002<\/p>\n\n\n\n
let a = undefined <\/code>\/\/ \u4e00\u822c\u4e0d\u4f1a\u8fd9\u4e48\u5199<\/code><\/em><\/pre>\n\n\n\n
\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08primitive\uff09<\/h2>\n\n\n\n
\u4e0a\u8ff0\u6211\u4eec\u6240\u8bf4\u7684\u51e0\u79cd\u6570\u636e\u7c7b\u578b\uff0c\u5305\u62ec\u6570\u5b57\uff08number\u548cbigint\uff09\u3001\u5b57\u7b26\u4e32\uff08string\uff09\u3001\u5e03\u5c14\u503c\uff08boolean\uff09\u3001\u7a7a\u503c\uff08null\uff09\u3001\u672a\u5b9a\u4e49\uff08undeifined\uff09\u3002\u8fd9\u4e9b\u503c\u5728JS\u4e2d\u88ab\u79f0\u4e3a\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08\u8fd8\u6709\u4e00\u4e2asymbol\u6ca1\u8bb2\uff09\u3002<\/p>\n\n\n\n
\u8fd9\u51e0\u79cd\u6570\u636e\u662f\u6784\u6210JS\u4e16\u754c\u4e2d\u4e00\u5207\u6570\u636e\u7684\u57fa\u77f3\uff0cJS\u4e2d\u4e00\u5207\u6570\u636e\u90fd\u662f\u6709\u8fd9\u4e9b\u5185\u5bb9\u6784\u6210\u7684\u3002\u8fd9\u4e9b\u6570\u636e\u90fd\u6709\u4e00\u4e2a\u5171\u540c\u7684\u7279\u70b9\uff1a\u201c\u4e0d\u53ef\u53d8\u201d\u3002\u57fa\u672c\u6570\u636e\u7c7b\u578b\u5728JS\u4e2d\u90fd\u662f\u4e0d\u53ef\u53d8\u6570\u636e\u3002<\/p>\n\n\n\n
\u4f55\u4e3a\u4e0d\u53ef\u53d8\u6570\u636e\uff1f\u8fd9\u4e9b\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u503c\u4e00\u65e6\u521b\u5efa\u5c31\u4e0d\u53ef\u66f4\u9ad8\u3002\u7b80\u5355\u6765\u8bf4\uff0c1\u6c38\u8fdc\u90fd\u662f1\uff0c\u4e0d\u4f1a\u53d8\u62102\u3002’hello’\uff08\u5b57\u7b26\u4e32\uff09\u6c38\u8fdc\u90fd\u662f’hello’\u6ca1\u6cd5\u53d8\u6210’abc’\u3002true\u3001false\u3001null\u3001undefined\u8fd9\u4e9b\u503c\u4e5f\u662f\u540c\u7406\uff0c\u6c38\u8fdc\u4e0d\u80fd\u88ab\u6539\u53d8\u3002\u5bf9\u4e8e\u521d\u5b66\u8005\u6765\u8bf4\uff0c\u4f3c\u4e4e\u4e0d\u592a\u597d\u7406\u89e3\uff0c\u4f46\u662f\u4e0d\u7740\u6025\u5148\u8bb0\u4f4f\u7ed3\u8bba\u3002<\/p>\n\n\n\n
\u8bf4\u5230\u8fd9\u6709\u4e9b\u5584\u4e8e\u601d\u8003\u7684\u540c\u5b66\u5c31\u6709\u7591\u95ee\u4e86\uff0c\u4e0d\u5bf9\u554a\u8001\u5e08\u4f60\u8bf4\u7684\u4e0d\u5bf9\uff0c\u57fa\u672c\u6570\u636e\u7c7b\u578b\u662f\u53ef\u4ee5\u6539\u53d8\u7684\uff0c\u6bd4\u5982\u8fd9\u6837\uff1a<\/p>\n\n\n\n
let  a = 10\na = 3<\/code><\/pre>\n\n\n\n
\u8fd9\u6837a\u7684\u503c\u4e0d\u5c31\u6539\u53d8\u4e86\u5417\uff1f\u600e\u4e48\u8bf4\u662f\u4e0d\u80fd\u53d8\u5462\uff1f<\/p>\n\n\n\n
\u8fd9\u4e2a\u95ee\u9898\u4f1a\u6709\u5f88\u591a\u540c\u5b66\u60f3\u4e0d\u660e\u767d\uff0c\u8fd9\u5c31\u8981\u6c42\u4f60\u5fc5\u987b\u8981\u660e\u786e\u7684\u533a\u5206\u51fa\u4e24\u4e2a\u6982\u5ff5\uff1a\u53d8\u91cf\u548c\u503c\uff08\u5b57\u9762\u91cf\uff09\u3002\u8fd9\u91cca\u662f\u53d8\u91cf\u800c10\u662f\u503c\uff0c\u6240\u4ee5\u6211\u8bf4\u4e0d\u53ef\u53d8\u6307\u7684\u662f\u201c\u503c10\u201d\u4e0d\u53ef\u53d8\u3002a = 3\u662f\u5728\u4e3a\u53d8\u91cf\u8fdb\u884c\u91cd\u65b0\u8d4b\u503c\uff0c\u662f\u5728\u6539\u53d8\u53d8\u91cf\u800c\u4e0d\u662f\u6539\u53d8\u503c\u3002\u50cf\u6211\u4eec\u4e4b\u524d\u8bf4\u7684\u53d8\u91cf\u76f8\u5f53\u4e8e\u503c\u7684\u522b\u540d\uff0clet a = 10\u8868\u793a\u7ed910\u8d77\u4e86\u4e00\u4e2a\u540d\u5b57\u53eba\uff0c\u800ca = 3\u8868\u793a\uff0c\u73b0\u572810\u4e0d\u53eba\u4e86\uff0c3\u53eba\u3002\u76f8\u5f53\u4e8e\u4fee\u6539\u4e8610\u7684\u522b\u540d\uff0c\u5bf9\u4e8e10\u672c\u8eab\u6765\u8bf4\u6709\u5f71\u54cd\u5417\uff1f\u6ca1\u6709\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6570\u5b57\u548c\u5b57\u7b26\u4e32\u662f\u6700\u6613\u4e8e\u7406\u89e3\u7684\u503c\u3002\u9664\u6b64\u4e4b\u5916\uff0cJS\u79cd\u8fd8\u6709\u51e0\u79cd\u503c\uff0c\u8fd9\u51e0\u79cd\u503c\u672c\u8eab\u6bd4\u8f83\u7b80\u5355\uff0c\u5c31\u653e\u5728\u4e00\u8d77\u8bf4\u4e86\u3002 \u5e03\u5c14\u503c\uff08bo […]<\/p>\n","protected":false},"author":1,"featured_media":6148,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[241],"tags":[200,244,234],"_links":{"self":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6046"}],"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=6046"}],"version-history":[{"count":2,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6046\/revisions"}],"predecessor-version":[{"id":6048,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6046\/revisions\/6048"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/media\/6148"}],"wp:attachment":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6046"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6046"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6046"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}