{"id":6276,"date":"2022-06-23T22:21:53","date_gmt":"2022-06-23T14:21:53","guid":{"rendered":"https:\/\/www.lilichao.com\/?p=6276"},"modified":"2022-10-14T15:41:47","modified_gmt":"2022-10-14T07:41:47","slug":"%e5%8e%9f%e5%a7%8b%e5%80%bc","status":"publish","type":"post","link":"https:\/\/lilichao.com\/?p=6276","title":{"rendered":"\u539f\u59cb\u503c"},"content":{"rendered":"\n<p>\u6570\u636e\u7c7b\u578b\uff0c\u6307\u90a3\u4e9b\u53ef\u4ee5\u8d4b\u503c\u7ed9\u53d8\u91cf\u7684\u503c\uff0cJS\u4e2d\u7684\u6570\u636e\u7c7b\u578b\u7531\u539f\u59cb\u503c\u548c\u5bf9\u8c61\u5171\u540c\u7ec4\u6210\u3002\u5bf9\u8c61\u6211\u4eec\u4f1a\u7a0d\u5fae\u665a\u70b9\u4ecb\u7ecd\uff0c\u5148\u6765\u4ecb\u7ecd\u539f\u59cb\u503c\u3002<\/p>\n\n\n\n<p>JavaScript\u4e2d\u4e00\u5171\u6709\u4e03\u79cd\u539f\u59cb\u503c\uff1a<\/p>\n\n\n\n<ol><li>\u6570\u503c\uff08Number\uff09<\/li><li>\u5927\u6574\u6570\uff08BigInt\uff09<\/li><li>\u5b57\u7b26\u4e32\uff08String\uff09<\/li><li>\u5e03\u5c14\u503c\uff08Boolean\uff09<\/li><li>\u7a7a\u503c\uff08Null\uff09<\/li><li>\u672a\u5b9a\u4e49\uff08Undefined\uff09<\/li><li>\u7b26\u53f7\uff08Symbol\uff09<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u6570\u503c\u548c\u5927\u6574\u6570<\/h2>\n\n\n\n<p>\u6570\u503c\u5c31\u662f\u6570\u5b57\uff0c\u5728JavaScript\u4e2d\u6570\u5b57\u6709\u4e24\u79cd\u666e\u901a\u7684\u6570\u503c\u548c\u5927\u6574\u6570\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u6570\u503c<\/h3>\n\n\n\n<p>\u5728JavaScript\u4e2d\u6574\u6570\u548c\u5c0f\u6570\u90fd\u662f\u6570\u503c\u7c7b\u578b\uff0c\u6570\u503c\u5e76\u4e0d\u662f\u65e0\u9650\u5927\u7684\uff0c\u5f53\u8d85\u8fc7\u4e00\u5b9a\u8303\u56f4\u540e\u6570\u503c\u4f1a\u81ea\u52a8\u663e\u793a\u8fd1\u4f3c\u503c\uff0c\u518d\u8d85\u8fc7\u8303\u56f4\u4f1a\u4ee5\u79d1\u5b66\u8ba1\u6570\u6cd5\u7684\u5f62\u5f0f\u663e\u793a\uff0c\u518d\u8d85\u8fc7\u8303\u56f4\u4f1a\u663e\u793a\u4e3a<code>Infinity<\/code>\u3002\u57fa\u4e8e\u6b64\u539f\u56e0\u518d\u52a0\u4e0a\u6d6e\u70b9\u6570\u8ba1\u7b97\u7684\u4e0d\u7cbe\u786e\u95ee\u9898\uff0c\u6240\u4ee5\u5c3d\u91cf\u4e0d\u8981\u76f4\u63a5\u4f7f\u7528\u6570\u503c\u505a\u4e00\u4e9b\u7cbe\u5ea6\u8981\u6c42\u8f83\u9ad8\u7684\u8fd0\u7b97\uff0c\u4f7f\u7528typeof\u8fd0\u7b97\u7b26\u68c0\u67e5\u4e00\u4e2a\u6570\u503c\u65f6\u4f1a\u8fd4\u56de<code>\"number\"<\/code>\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = 10\nlet b = 2.5\nlet c = 9999999999999991 \/\/ 9999999999999992\nlet d = 999999999999999999999 \/\/ 1e+21\nlet e = 999 ** 999 \/\/ Infinity\nlet f = 1.9999999999999999 \/\/ 2\nlet g = 0.0000005 \/\/ 5e-7<\/code><\/pre>\n\n\n\n<p>\u9664\u4e86\u5e38\u89c4\u7684\u6570\u5b57\u5916\uff0c\u5728\u6570\u503c\u4e2d\u8fd8\u5b58\u5728\u4e24\u4e2a\u7279\u6b8a\u503c<code>NaN<\/code>\u548c<code>Infinity<\/code>\u3002<\/p>\n\n\n\n<p>NaN \u2014\u2014 \u9519\u8bef\u7684\u6570\u503c<\/p>\n\n\n\n<p>Infinity \u2014\u2014 \u65e0\u7a77<\/p>\n\n\n\n<p>\u5176\u4ed6\u8fdb\u5236\u6570\u5b57\u7684\u8868\u793a\u65b9\u6cd5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = 0b1010 \/\/ \u4e8c\u8fdb\u5236\nlet b = 0o77 \/\/ \u516b\u8fdb\u5236\nlet c = 0xff \/\/ \u5341\u516d\u8fdb\u5236<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u5927\u6574\u6570<\/h3>\n\n\n\n<p>\u5927\u6574\u6570\uff0c\u987e\u540d\u601d\u4e49\u7528\u6765\u8868\u793a\u4e00\u4e9b\u6bd4\u8f83\u5927\u7684\u6574\u6570\uff0c\u6ce8\u610f\u53ea\u662f\u6574\u6570\u3002\u5927\u6574\u6570\u4f7f\u7528n\u7ed3\u5c3e\uff0c\u5927\u6574\u6570\u53ef\u4ee5\u662f\u65e0\u9650\u5927\u7684\uff08\u8fd8\u8981\u770b\u4f60\u7684\u5185\u5b58\u5927\u5199\uff09\uff0c\u4e14\u5927\u6574\u6570\u53ea\u80fd\u548c\u5927\u6574\u6570\u8ba1\u7b97\uff0c\u548c\u6570\u503c\u8ba1\u7b97\u4f1a\u62a5\u9519\u3002\u4f7f\u7528typeof\u68c0\u67e5\u4e00\u4e2a\u5927\u6574\u6570\u65f6\u4f1a\u8fd4\u56de<code>\"bigint\"<\/code><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = 9999999999999999999999n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u5b57\u7b26\u4e32<\/h2>\n\n\n\n<p>JavaScript\u4e2d\u5b57\u7b26\u4e32\u9700\u8981\u4f7f\u7528\u5f15\u53f7\u5f15\u8d77\u6765\uff0c\u5355\u5f15\u53f7\u548c\u53cc\u5f15\u53f7\u90fd\u662f\u53ef\u4ee5\u7684\uff0c\u6ca1\u6709\u672c\u8d28\u533a\u522b\u3002\u4f7f\u7528typeof\u8fd0\u7b97\u7b26\u68c0\u67e5\u4e00\u4e2a\u5b57\u7b26\u4e32\u65f6\u4f1a\u8fd4\u56de<code>\"string\"<\/code>\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = \"\u4eca\u5929\u5929\u6c14\u771f\u4e0d\u9519\"\nlet b = '\u6628\u5929\u5929\u6c14\u4e5f\u633a\u597d'<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u8f6c\u4e49\u5b57\u7b26<\/h3>\n\n\n\n<p>JavaScript\u4e2d\u4f7f\u7528<code>\/<\/code>\u4f5c\u4e3a\u8f6c\u4e49\u5b57\u7b26\uff0c\u8f6c\u4e49\u5b57\u7b26\u7528\u4ee5\u8868\u793a\u4e00\u4e9b\u7279\u6b8a\u7684\u7b26\u53f7\uff0c\u6bd4\u5982\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\">\u8f6c\u4e49\u5b57\u7b26<\/td><td class=\"has-text-align-center\" data-align=\"center\">\u5b57\u7b26\u4e32<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\&#8217;<\/td><td class=\"has-text-align-center\" data-align=\"center\">&#8216;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\&#8221;<\/td><td class=\"has-text-align-center\" data-align=\"center\">&#8220;<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\\\<\/td><td class=\"has-text-align-center\" data-align=\"center\">\\<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\n<\/td><td class=\"has-text-align-center\" data-align=\"center\">\u6362\u884c<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\t<\/td><td class=\"has-text-align-center\" data-align=\"center\">\u5236\u8868\u7b26<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\\uxxxx<\/td><td class=\"has-text-align-center\" data-align=\"center\">Unicode\u7f16\u7801<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u6a21\u677f\u5b57\u7b26\u4e32<\/h3>\n\n\n\n<p>\u6a21\u677f\u5b57\u7b26\u4e32\u53ef\u4ee5\u7528\u6765\u8868\u793a\u4e00\u4e9b\u6bd4\u8f83\u957f\u7684\u5b57\u7b26\u4e32\uff08\u8de8\u884c\uff09\uff0c\u4e14\u53ef\u4ee5\u76f4\u63a5\u5411\u5b57\u7b26\u4e32\u4e2d\u5d4c\u5165\u53d8\u91cf\uff0c\u4f7f\u7528<code>`<\/code>\u8868\u793a\u6a21\u677f\u5b57\u7b26\u4e32\uff0c\u5728\u6a21\u677f\u5b57\u7b26\u4e32\u4e2d\u4f7f\u7528<code>${\u53d8\u91cf}<\/code>\u6765\u5d4c\u5165\u53d8\u91cf\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let str = `\u9504\u79be\u65e5\u5f53\u5348\n\u6c57\u6ef4\u79be\u4e0b\u571f\n\u8c01\u77e5\u76d8\u4e2d\u9910\n\u7c92\u7c92\u7686\u8f9b\u82e6\n`<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>let name = \"\u5b59\u609f\u7a7a\"\nlet str = `\u5927\u5bb6\u597d\uff0c\u6211\u662f${name}`<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u5e03\u5c14\u503c<\/h2>\n\n\n\n<p>\u5e03\u5c14\u503c\u7528\u6765\u8fdb\u884c\u903b\u8f91\u5224\u65ad\uff0c\u53ea\u6709\u4e24\u4e2a<code>true<\/code>\u548c<code>false<\/code>\u3002\u4f7f\u7528typeof\u68c0\u67e5\u65f6\u4f1a\u8fd4\u56de<code>\"boolean\"<\/code><\/p>\n\n\n\n<p>true \u2014\u2014 \u771f<\/p>\n\n\n\n<p>false \u2014\u2014 \u5047<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = true\nlet b = false<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u7a7a\u503c<\/h2>\n\n\n\n<p>\u7a7a\u503c\u8868\u793a\u7a7a\u3001\u4e0d\u5b58\u5728\uff0c\u53ea\u6709\u4e00\u4e2a\u503c<code>null<\/code>\u3002\u4f7f\u7528typeof\u68c0\u67e5\u65f6\u4f1a\u8fd4\u56de<code>\"object\"<\/code><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = null<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u672a\u5b9a\u4e49<\/h2>\n\n\n\n<p>\u672a\u5b9a\u4e49\uff0c\u4f5c\u7528\u548c\u7a7a\u503c\u7c7b\u4f3c\uff0c\u540c\u6837\u53ea\u6709\u4e00\u4e2a\u503c<code>undefined<\/code>\u3002\u6211\u4eec\u4e00\u822c\u4e0d\u4f1a\u4e3b\u52a8\u4f7f\u7528undefined\u3002\u4f7f\u7528typeof\u68c0\u67e5\u65f6\u4f1a\u8fd4\u56de<code>\"undefined\"<\/code><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a \/\/ \u6b64\u65f6a\u7684\u503c\u5c31\u662fundefined<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u7b26\u53f7<\/h2>\n\n\n\n<p>\u7b26\u53f7\u6bd4\u8f83\u7279\u6b8a\uff0c\u7528\u4ee5\u8868\u793a\u4e00\u4e2a\u552f\u4e00\u6807\u8bc6\uff0c\u5728\u4e00\u4e9b\u7279\u6b8a\u573a\u666f\u4e0b\u56de\u4f7f\u7528\uff0c\u73b0\u5728\u7b80\u5355\u4e86\u89e3\u4e00\u4e0b\u5373\u53ef\u3002\u4f7f\u7528typeof\u68c0\u67e5\u4e00\u4e2a\u7b26\u53f7\u65f6\u4f1a\u8fd4\u56de<code>\"symbol\"<\/code><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let a = Symbol()<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u539f\u59cb\u503c\u90fd\u662f\u4e0d\u53ef\u53d8\u7684<\/h2>\n\n\n\n<p>\u4e0a\u8fb9\u6240\u6709\u7684\u539f\u59cb\u503c\u90fd\u662f\u4e0d\u53ef\u53d8\u7684\u7c7b\u578b\uff0c\u503c\u4e00\u65e6\u521b\u5efa\u5c31\u65e0\u6cd5\u4fee\u6539\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6570\u636e\u7c7b\u578b\uff0c\u6307\u90a3\u4e9b\u53ef\u4ee5\u8d4b\u503c\u7ed9\u53d8\u91cf\u7684\u503c\uff0cJS\u4e2d\u7684\u6570\u636e\u7c7b\u578b\u7531\u539f\u59cb\u503c\u548c\u5bf9\u8c61\u5171\u540c\u7ec4\u6210\u3002\u5bf9\u8c61\u6211\u4eec\u4f1a\u7a0d\u5fae\u665a\u70b9\u4ecb\u7ecd\uff0c\u5148\u6765\u4ecb\u7ecd\u539f [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6287,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[241,231],"tags":[200,244],"_links":{"self":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6276"}],"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=6276"}],"version-history":[{"count":6,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6276\/revisions"}],"predecessor-version":[{"id":6492,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6276\/revisions\/6492"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/media\/6287"}],"wp:attachment":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}