NaN评估背后的逻辑是什么?(What logic is behind NaN evaluation? [duplicate])
这个问题在这里已有答案:
为什么NaN === NaN是假的? [重复] 3个答案你能解释一下NaN中NaN的逻辑评估吗?
NaN==NaN (false) !NaN==!NaN (true) NaN!=NaN (true) NaN==false (false) NaN==true (false)我在这里有点惊讶......
This question already has an answer here:
Why is NaN === NaN false? [duplicate] 3 answersCan you explain the logical evaluation of NaN in javascript?
NaN==NaN (false) !NaN==!NaN (true) NaN!=NaN (true) NaN==false (false) NaN==true (false)I am a little surprised here...
最满意答案
因为这就是规范所说的。
具体来说,IEE浮点规范说NaN不等于自己。 因此,在Javascript中,没有NaN可以相等的值。
!NaN是true ,因为NaN是一个假值。
这使您的所有示例都显而易见。
Because that's what the spec says.
Specifically, the IEE floating point spec says that NaN does not equal itself. Therefore, in Javascript, there is no value that NaN can ever equal.
!NaN is true, because NaN is a falsy value.
This makes all of your examples obvious.
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