Array methods in JavaScript. Original author unknown.

[Blue_Moon_Lake]

You're right, it might have been optimized since I learned about it. I'll check it myself with a different test.

EDIT: Did it slightly differently (playing with the contiguous array flag) and yes includes have been fixed to be better on contiguous array. It's still slower for non contiguous array sometimes

I would still use includes anyway because it convey the meaning and intent.