typeof \u662f\u4e00\u4e2a\u4e00\u5143\u8fd0\u7b97,\u653e\u5728\u4e00\u4e2a\u8fd0\u7b97\u6570\u4e4b\u524d,\u8fd0\u7b97\u6570\u53ef\u4ee5\u662f\u4efb\u610f\u7c7b\u578b.
\u5b83\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32,\u8be5\u5b57\u7b26\u4e32\u8bf4\u660e\u8fd0\u7b97\u6570\u7684\u7c7b\u578b.<\/p>\n
\u4f60\u77e5\u9053\u4e0b\u9762typeof\u8fd0\u7b97\u7684\u7ed3\u679c\u5417?<\/p>\n
typeof(1);
typeof(NaN);
typeof(Number.MIN_VALUE);
typeof(Infinity);
typeof(“123”);
typeof(true);
typeof(window);
typeof(document);
typeof(null);
typeof(eval);
typeof(Date);
typeof(sss);
typeof(undefined);<\/p>\n
\u770b\u770b\u4f60\u4f1a\u51e0\u4e2a?<\/p>\n
\u5982\u679c\u770b\u4e86\u4ee5\u540e,\u4e0d\u662f\u5f88\u660e\u767d\u7684\u8bdd,\u8bf7\u770b\u4e0b\u9762\uff1a
typeof\u662f\u4e00\u4e2a\u4e00\u5143\u8fd0\u7b97\u7b26,\u5b83\u8fd4\u56de\u7684\u7ed3\u679c\u59cb\u7ec8\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32,\u5bf9\u4e0d\u540c\u7684\u64cd\u4f5c\u6570,\u5b83\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c.
\u5177\u4f53\u7684\u89c4\u5219\u5982\u4e0b\uff1a
\u4e00\u3001\u5bf9\u4e8e\u6570\u5b57\u7c7b\u578b\u7684\u64cd\u4f5c\u6570\u800c\u8a00, typeof \u8fd4\u56de\u7684\u503c\u662f number.\u6bd4\u5982\u8bf4\uff1atypeof(1),\u8fd4\u56de\u7684\u503c\u5c31\u662fnumber.
\u4e0a\u9762\u662f\u4e3e\u7684\u5e38\u89c4\u6570\u5b57,\u5bf9\u4e8e\u975e\u5e38\u89c4\u7684\u6570\u5b57\u7c7b\u578b\u800c\u8a00,\u5176\u7ed3\u679c\u8fd4\u56de\u7684\u4e5f\u662fnumber.\u6bd4\u5982typeof(NaN),NaN\u5728
JavaScript\u4e2d\u4ee3\u8868\u7684\u662f\u7279\u6b8a\u975e\u6570\u5b57\u503c,\u867d\u7136\u5b83\u672c\u8eab\u662f\u4e00\u4e2a\u6570\u5b57\u7c7b\u578b.
\u5728JavaScript\u4e2d,\u7279\u6b8a\u7684\u6570\u5b57\u7c7b\u578b\u8fd8\u6709\u51e0\u79cd\uff1a
Infinity \u8868\u793a\u65e0\u7a77\u5927\u7279\u6b8a\u503c
NaN\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u7279\u6b8a\u7684\u975e\u6570\u5b57\u503c
Number.MAX_VALUE\u3000\u3000\u3000\u3000\u3000\u53ef\u8868\u793a\u7684\u6700\u5927\u6570\u5b57
Number.MIN_VALUE\u3000\u3000\u3000\u3000\u3000\u53ef\u8868\u793a\u7684\u6700\u5c0f\u6570\u5b57\uff08\u4e0e\u96f6\u6700\u63a5\u8fd1\uff09
Number.NaN\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u7279\u6b8a\u7684\u975e\u6570\u5b57\u503c
Number.POSITIVE_INFINITY\u3000\u8868\u793a\u6b63\u65e0\u7a77\u5927\u7684\u7279\u6b8a\u503c
Number.NEGATIVE_INFINITY \u8868\u793a\u8d1f\u65e0\u7a77\u5927\u7684\u7279\u6b8a\u503c<\/p>\n
\u4ee5\u4e0a\u7279\u6b8a\u7c7b\u578b,\u5728\u7528typeof\u8fdb\u884c\u8fd0\u7b97\u8fdb,\u5176\u7ed3\u679c\u90fd\u5c06\u662fnumber.<\/p>\n
\u4e8c\u3001\u5bf9\u4e8e\u5b57\u7b26\u4e32\u7c7b\u578b, typeof \u8fd4\u56de\u7684\u503c\u662f string.\u6bd4\u5982typeof(“123”)\u8fd4\u56de\u7684\u503c\u662fstring.
\u4e09\u3001\u5bf9\u4e8e\u5e03\u5c14\u7c7b\u578b, typeof \u8fd4\u56de\u7684\u503c\u662f boolean .\u6bd4\u5982typeof(true)\u8fd4\u56de\u7684\u503c\u662fboolean.
\u56db\u3001\u5bf9\u4e8e\u5bf9\u8c61\u3001\u6570\u7ec4\u3001null \u8fd4\u56de\u7684\u503c\u662f object .\u6bd4\u5982typeof(window),typeof(document),typeof(null)\u8fd4\u56de\u7684\u503c\u90fd\u662fobject.
\u4e94\u3001\u5bf9\u4e8e\u51fd\u6570\u7c7b\u578b,\u8fd4\u56de\u7684\u503c\u662f function.\u6bd4\u5982\uff1atypeof(eval),typeof(Date)\u8fd4\u56de\u7684\u503c\u90fd\u662ffunction.
\u516d\u3001\u5982\u679c\u8fd0\u7b97\u6570\u662f\u6ca1\u6709\u5b9a\u4e49\u7684\uff08\u6bd4\u5982\u8bf4\u4e0d\u5b58\u5728\u7684\u53d8\u91cf\u3001\u51fd\u6570\u6216\u8005undefined\uff09,\u5c06\u8fd4\u56deundefined.\u6bd4\u5982\uff1atypeof(sss)\u3001typeof(undefined)\u90fd\u8fd4\u56deundefined.<\/p>\n","protected":false},"excerpt":{"rendered":"
typeof \u662f\u4e00\u4e2a\u4e00\u5143\u8fd0\u7b97,\u653e\u5728\u4e00\u4e2a\u8fd0\u7b97\u6570\u4e4b\u524d,\u8fd0\u7b97\u6570\u53ef\u4ee5\u662f\u4efb\u610f\u7c7b\u578b.\u5b83\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32,\u8be5\u5b57\u7b26\u4e32\u8bf4\u660e\u8fd0\u7b97 … Continue reading JavaScript\u4e2d\u7684typeof\u89e3\u91ca<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-500","post","type-post","status-publish","format-standard","hentry","without-featured-image"],"_links":{"self":[{"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/posts\/500","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/1vr.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=500"}],"version-history":[{"count":2,"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/posts\/500\/revisions"}],"predecessor-version":[{"id":839,"href":"https:\/\/1vr.cn\/index.php?rest_route=\/wp\/v2\/posts\/500\/revisions\/839"}],"wp:attachment":[{"href":"https:\/\/1vr.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=500"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/1vr.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=500"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/1vr.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=500"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}