{"id":207143,"date":"2025-07-08T09:38:01","date_gmt":"2025-07-08T01:38:01","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207143\/"},"modified":"2025-07-08T09:38:01","modified_gmt":"2025-07-08T01:38:01","slug":"f-f-%e4%bb%80%e4%b9%88%e6%97%b6%e5%80%99%e5%8f%af%e8%83%bd%e4%b8%ba%e7%9c%9f%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207143\/","title":{"rendered":"f != f \u4ec0\u4e48\u65f6\u5019\u53ef\u80fd\u4e3a\u771f\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<p>\u5f53\u524d\u4f4d\u7f6e\uff1a <span>&gt;<\/span> <span>&gt;<\/span> <span>&gt;<\/span> <span>&gt;<\/span> <span>f != f \u4ec0\u4e48\u65f6\u5019\u53ef\u80fd\u4e3a\u771f\uff1f<\/span><\/p>\n<p><span>\u6765\u6e90\uff1astackoverflow<\/span><br \/>\n<span>2024-04-20 12:39:37<\/span><br \/>\n<span><i><\/i>0\u6d4f\u89c8<\/span><br \/>\n<span style=\"cursor: pointer\"><i><\/i>\u6536\u85cf<\/span> <\/p>\n<p>\u54c8\u55bd\uff01\u4eca\u5929\u5fc3\u8840\u6765\u6f6e\u7ed9\u5927\u5bb6\u5e26\u6765\u4e86<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u300af != f \u4ec0\u4e48\u65f6\u5019\u53ef\u80fd\u4e3a\u771f\uff1f\u300b<\/span>\uff0c\u60f3\u5fc5\u5927\u5bb6\u5e94\u8be5\u5bf9<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">Golang<\/span>\u90fd\u4e0d\u964c\u751f\u5427\uff0c\u90a3\u4e48\u9605\u8bfb\u672c\u6587\u5c31\u90fd\u4e0d\u4f1a\u5f88\u56f0\u96be\uff0c\u4ee5\u4e0b\u5185\u5bb9\u4e3b\u8981\u6d89\u53ca\u5230<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\"><\/span>\uff0c\u82e5\u662f\u4f60\u6b63\u5728\u5b66\u4e60<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">Golang<\/span>\uff0c\u5343\u4e07\u522b\u9519\u8fc7\u8fd9\u7bc7\u6587\u7ae0~\u5e0c\u671b\u80fd\u5e2e\u52a9\u5230\u4f60\uff01<\/p>\n<p> \u95ee\u9898\u5185\u5bb9<br \/>\n <\/p>\n<p>\u8c01\u80fd\u8be6\u7ec6\u8bf4\u660e\u4e00\u4e0b<code>syscalls\/js<\/code>\u7684\u4e3b\u9898\uff0c\u4e3a\u4ec0\u4e48\u5728\u7b2c57\u884c\u6709\u4e00\u4e2a\u58f0\u660e<\/p>\n<pre>if f != f { ... }<\/pre>\n<p>\uff08<code>f<\/code> \u7684\u7c7b\u578b\u4e3a <code>float64<\/code>\uff09\u3002<\/p>\n<p>\u8fd9\u600e\u4e48\u53ef\u80fd\uff1f <code>i != i<\/code> \u8fd9\u6837\u7684\u8bed\u53e5\u4ec0\u4e48\u65f6\u5019\u53ef\u4ee5\u5728 <code>go<\/code> \u4e2d\u6210\u4e3a <code>true<\/code> \uff1f<\/p>\n<p> <\/p>\n<h2>\u89e3\u51b3\u65b9\u6848<\/h2>\n<p> <\/p>\n<p>\u4f8b\u5982\uff0c\u5982\u679c <code>f<\/code> \u7684\u7c7b\u578b\u4e3a <code>float64<\/code>\uff0c\u5e76\u4e14\u5176\u503c\u662f\u8868\u793a\u201c\u4e0d\u662f\u6570\u5b57\u201d\u7684\u7279\u5b9a\u503c\uff0c\u60a8\u53ef\u4ee5\u4ece \u83b7\u53d6\u8be5\u503c\u3002 <code>nan<\/code> \u6839\u636e\u5b9a\u4e49\uff0c\u4e0d\u7b49\u4e8e\u4efb\u4f55\u5176\u4ed6 <code>float64<\/code> \u503c\uff0c\u5305\u62ec zqbczq bnan \u672c\u8eab\u3002 <code>float64<\/code> \u7c7b\u578b\u4f7f\u7528 \u6807\u51c6\uff0c\u8be5\u6807\u51c6\u8868\u793a\u53ea\u6709 <code>nan<\/code> \u6ee1\u8db3 <code>f != f<\/code> \u4e0d\u7b49\u5f0f\u3002<\/p>\n<pre>var f float64 = math.NaN()\nfmt.Println(f != f)<\/pre>\n<p>\u8fd9\u5c06\u6253\u5370 <code>true<\/code>\uff0c\u8bf7\u5728 \u4e0a\u5c1d\u8bd5\u4e00\u4e0b\u3002<\/p>\n<p>\u63a8\u7406\u53c2\u89c1<\/p>\n<p>\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300af != f \u4ec0\u4e48\u65f6\u5019\u53ef\u80fd\u4e3a\u771f\uff1f\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591aGolang\u77e5\u8bc6\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5f53\u524d\u4f4d\u7f6e\uff1a &gt; &gt; &#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207143","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=207143"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207143\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}