[Szpadel]

well there is also one weird quirk I I assumed will be also included in this article:

because a <= b is defined as !(a > b)

then:

5 < NaN // false

5 == NaN // false

5 <= NaN // true

Edit: my bad, this does not work with NaN, but you can try `0 <= null`

[lifthrasiir]

IEEE 754 specifically prohibits that definition, and JavaScript indeed evaluates `5 <= NaN` to false.

[Szpadel]

Yep, my memory was incorrect here and I didn't had access to computer, but it is true with `0 <= null`

[kaoD]

This is because null coerces to 0 in JS so this is effectively 0 <= 0. NaN is already a `number` so no coercion happens.

Note that == has special rules, so 0 == null does NOT coerce to 0 == 0. If using == null, it only equals undefined and itself.