NaN是否等于NaN？ [英] Is NaN equal to NaN?

问题描述

parseFloat("NaN")

返回NaN ，但是

returns "NaN", but

parseFloat("NaN") == "NaN"

返回false。现在，这可能是一件好事，它确实会返回false，但我不明白这是怎么回事。 JavaScript创作者是否只是将其作为特例？

returns false. Now, that's probably a good thing that it does return false, but I don't understand how this is so. Did the JavaScript creators just make this a special case? Because otherwise I can't understand how this returns false.

推荐答案

当JavaScript函数返回 NaN ，这不是一个文字字符串，而是全局空间中的对象属性。您无法将它与字符串NaN进行比较。

When a JavaScript function returns NaN, this is not a literal string but an object property in the global space. You cannot compare it to the string "NaN".

请参阅 https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/NaN

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