Hacker News Reader

I'm not sure that's right. 1/0 is undefined NOT infinity, hence -1/0 is also undefined. So actually line 3 should evaluate as true.

NaN === NaN evaluates to false. That’s what happens here, not anything with Infinity.

Yeah, that makes sense mostly. But why is NaN === NaN false? What am I missing here?

Because there is many ways NaN can be generated, all very different.

== is only defined for numbers, too.

1/0 and 50/0 aren’t the same, for example.

just type them in your console instead of saying wrong things

Then they don’t conform to the IEEE standards, and the Javascript implementers are wrong.

NaN !== NaN is just right

Yes, but 1/0 === Infinity isn’t. That number is very different from Infinity.