That's hilarious.

What's not hilarious is that, after removing the essentially useless error-checking, is-even is literally just `(n % 2) === 1`. On one hand, JS desperately needs a standard library, on the other hand, JS devs can be so infuriatingly lazy and obtuse.

> is-even is literally just `(n % 2) === 1`

Pretty sure that tells you if a number is odd. I guess maybe there is a reason these libraries exist.

That was just a typo, I meant the source for is-odd. I copy-pasted it. I use that exact syntax all the time in code, you don't need to be patronizing.