NaN是什么 NaN == NaN 的结果是什么?为什么? - 知乎 NaN与任何其他值（包括NaN本身）进行比较的结果都是false，包括NaN == NaN。 这是因为NaN被定义为不等于任何其他值，甚至不等于它自己。 这是由于NaN的特殊性质导致的。 NaN的比较结果为false的原因是为了遵循IEEE 754浮点数标准，该标准规定了浮点数的比较方式。
floating point - Why is NaN not equal to NaN? - Stack Overflow NaN is designed to propagate through all calculations, infecting them like a virus, so if somewhere in your deep, complex calculations you hit upon a NaN, you don't bubble out a seemingly sensible answer Otherwise by identity NaN NaN should equal 1, along with all the other consequences like (NaN NaN)==1, (NaN*1)==NaN, etc
What is NaN (Not a Number) in the words of a beginner? What is a NaN value or NaN exactly (in the words of a non-math professor)? Let's suppose you're working with real numbers - numbers like 1, π, e, -137, 6 626, etc In the land of real numbers, there are some operations that usually can be performed, but sometimes don't have a defined result For example, let's look at logarithms
How do you check that a number is NaN in JavaScript? 182 I just came across this technique in the book Effective JavaScript that is pretty simple: Since NaN is the only JavaScript value that is treated as unequal to itself, you can always test if a value is NaN by checking it for equality to itself:
javascript - ¿Por qué NaN != NaN? - Stack Overflow en español Tenía tiempo programando en JavaScript y nunca me había dado cuenta de esa peculiaridad que tiene con el valor NaN Decidí investigar y lo más que encontré fue: NaN - JavaScript | MDN [inglés]
javascript - Is NaN equal to NaN? - Stack Overflow 37 It's a special case, NaN is the only thing in Javascript not equal to itself Although the other answers about strings vs the NaN object are right too