{"id":663,"date":"2009-02-12T17:02:26","date_gmt":"2009-02-12T09:02:26","guid":{"rendered":"http:\/\/fdream.net\/blog\/article\/663.aspx"},"modified":"2009-02-12T17:02:32","modified_gmt":"2009-02-12T09:02:32","slug":"JavaScript%e5%a5%87%e6%80%aa%e7%9a%84%e6%af%94%e8%be%83%e2%80%94%e2%80%94%e9%9a%90%e5%bc%8f%e7%b1%bb%e5%9e%8b%e8%bd%ac%e6%8d%a2","status":"publish","type":"post","link":"https:\/\/fdream.net\/blog\/article\/663","title":{"rendered":"JavaScript\u5947\u602a\u7684\u6bd4\u8f83\u2014\u2014\u9690\u5f0f\u7c7b\u578b\u8f6c\u6362"},"content":{"rendered":"<p>\u6211\u4eec\u5148\u770b\u4e00\u4e0bJavaScript\u4e2d\u5173\u7cfb\u8fd0\u7b97\u7b26\u7684\u7c7b\u578b\u8f6c\u6362\u89c4\u5219\uff1a<\/p>\n<blockquote>\n<p><b>\u5173\u7cfb\u8fd0\u7b97\u7b26\uff08<\u3001>\u3001<=\u3001>=\uff09 <\/b><\/p>\n<ul style=\"list-style-type:disc\">\n<li>\u8bd5\u56fe\u5c06 expression1 \u548c expression2 \u90fd\u8f6c\u6362\u4e3a\u6570\u5b57\u3002 <\/li>\n<li>\u5982\u679c\u4e24\u8868\u8fbe\u5f0f\u5747\u4e3a\u5b57\u7b26\u4e32\uff0c\u5219\u6309\u5b57\u5178\u5e8f\u8fdb\u884c\u5b57\u7b26\u4e32\u6bd4\u8f83\u3002 <\/li>\n<li>\u5982\u679c\u5176\u4e2d\u4e00\u4e2a\u8868\u8fbe\u5f0f\u4e3a NaN\uff0c\u8fd4\u56de false\u3002 <\/li>\n<li>\u8d1f\u96f6\u7b49\u4e8e\u6b63\u96f6\u3002 <\/li>\n<li>\u8d1f\u65e0\u7a77\u5c0f\u4e8e\u5305\u62ec\u5176\u672c\u8eab\u5728\u5185\u7684\u4efb\u4f55\u6570\u3002 <\/li>\n<li>\u6b63\u65e0\u7a77\u5927\u4e8e\u5305\u62ec\u5176\u672c\u8eab\u5728\u5185\u7684\u4efb\u4f55\u6570\u3002<\/li>\n<\/ul>\n<\/blockquote>\n<p>\u6240\u4ee5\u5f88\u5bb9\u6613\u7406\u89e3\u4e0b\u9762\u8fd9\u6837\u7684\u6bd4\u8f83\uff1a<\/p>\n<pre lang=\"javascript\">\n1 &lt; NaN: false\n1 &gt;= NaN: false\n\n'a' &lt; 1: false\n'a' &gt;= 1: false\n<\/pre>\n<\/p>\n<p>\u4f46\u662f\u4e0b\u9762\u7684\u5c31\u5f88\u8be1\u5f02\u4e86\uff1a<\/p>\n<p><pre lang=\"javascript\">\n1 &lt; '2a': false\n1 &gt;= '2a': false\n'2a' &lt; 1: false\n'2a' &gt;= 1: false\n<\/pre>\n<\/p>\n<p>\u6309\u7167\u4e00\u822c\u7684\u7406\u89e3\uff0c\u8fd9\u91cc\u7684&#8217;2a&#8217;\u5e94\u8be5\u4f1a\u88ab\u8f6c\u6362\u62102\uff0c\u53ef\u662f\u5b9e\u9645\u4e0a\u662f\u88ab\u8f6c\u6362\u6210\u4e86NaN\uff0cwhy\uff1f\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u6570\u5b57\uff0c\u6709parseInt()\u3001parseFloat()\u548cNumber()\uff0c\u5728\u8fd9\u91cc\u4f7f\u7528\u7684\u5c31\u662fNumber\u8f6c\u6362\u3002\u5728\u7528Number()\u8fdb\u884c\u8f6c\u6362\u65f6\uff0c&#8217;2a&#8217;\u662f\u4e0d\u80fd\u88ab\u8f6c\u6362\u6210\u6570\u5b57\u7684\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6211\u4eec\u5148\u770b\u4e00\u4e0bJavaScript\u4e2d\u5173\u7cfb\u8fd0\u7b97\u7b26\u7684\u7c7b\u578b\u8f6c\u6362\u89c4\u5219\uff1a \u5173\u7cfb\u8fd0\u7b97\u7b26\uff08\u3001=\uff09 \u8bd5\u56fe\u5c06 expression1 \u548c expression2 \u90fd\u8f6c\u6362\u4e3a\u6570\u5b57\u3002 \u5982\u679c\u4e24\u8868\u8fbe\u5f0f\u5747\u4e3a\u5b57\u7b26\u4e32\uff0c\u5219\u6309\u5b57\u5178\u5e8f\u8fdb\u884c\u5b57\u7b26\u4e32\u6bd4\u8f83\u3002 \u5982\u679c\u5176\u4e2d\u4e00\u4e2a\u8868\u8fbe\u5f0f\u4e3a NaN\uff0c\u8fd4\u56de false\u3002 \u8d1f\u96f6\u7b49\u4e8e\u6b63\u96f6\u3002 \u8d1f\u65e0\u7a77\u5c0f\u4e8e\u5305\u62ec\u5176\u672c\u8eab\u5728\u5185\u7684\u4efb\u4f55\u6570\u3002 \u6b63\u65e0\u7a77\u5927\u4e8e\u5305\u62ec\u5176\u672c\u8eab\u5728\u5185\u7684\u4efb\u4f55\u6570\u3002 \u6240\u4ee5\u5f88\u5bb9\u6613\u7406\u89e3\u4e0b\u9762\u8fd9\u6837\u7684\u6bd4\u8f83\uff1a 1 &lt; NaN: false 1 &gt;= NaN: false &#8216;a&#8217; &lt; 1: false &#8216;a&#8217; &gt;= 1: false \u4f46\u662f\u4e0b\u9762\u7684\u5c31\u5f88\u8be1\u5f02\u4e86\uff1a 1 &lt; &#8216;2a&#8217;: false 1 &gt;= &#8216;2a&#8217;: false &#8216;2a&#8217; &lt; 1: false &#8216;2a&#8217; &gt;= 1: false \u6309\u7167\u4e00\u822c\u7684\u7406\u89e3\uff0c\u8fd9\u91cc\u7684&#8217;2a&#8217;\u5e94\u8be5\u4f1a\u88ab\u8f6c\u6362\u62102\uff0c\u53ef\u662f\u5b9e\u9645\u4e0a\u662f\u88ab\u8f6c\u6362\u6210\u4e86NaN\uff0cwhy\uff1f\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u6570\u5b57\uff0c\u6709parseInt()\u3001parseFloat()\u548cNumber()\uff0c\u5728\u8fd9\u91cc\u4f7f\u7528\u7684\u5c31\u662fNumber\u8f6c\u6362\u3002\u5728\u7528Number()\u8fdb\u884c\u8f6c\u6362\u65f6\uff0c&#8217;2a&#8217;\u662f\u4e0d\u80fd\u88ab\u8f6c\u6362\u6210\u6570\u5b57\u7684\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[120,104],"class_list":["post-663","post","type-post","status-publish","format-standard","hentry","category-coding","tag-AJAX","tag-JavaScript"],"views":6957,"_links":{"self":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts\/663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/comments?post=663"}],"version-history":[{"count":0,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts\/663\/revisions"}],"wp:attachment":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/media?parent=663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/categories?post=663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/tags?post=663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}