[JohnWhigham]

Yes, JavaScript is a joke for having such a barren standard library that the community has to do it for them.

[jraph]

Ok, which programming languages actually have an isOdd or an isEven function in their standard library?

Anyway, Javascript, like virtually every programming language, has "& 1".

Yes, the standard library is lacking and yes, that's a big issue, partly responsible for the huge mess that is NPM. No, it does not matter one bit here so this is off topic.

[lotsofcows]

Gosh, never look at C. You'd break ribs.