[nobleach]

>new language construct

This was added to the language 10 years ago. So while it's "newer" than a plain old for-loop, it's definitely not "new". It was designed to work with Symbol.iterator. This is the mechanism whereby one can iterate anything that implements the Symbol.iterator interface.

As far as why folks won't just do simple for-loops, it's the same reasining every language tends to implement a "foreach", because there are annoying off-by-one errors lurking in the < vs <=. Of course one could argue that developers should be smart enough to handle this. But that's an argument even older than for-loops.

[trgn]

> here are annoying off-by-one errors

These barely if ever happen for simple iterations, it's an idee fixe. Off-by-one sneak in when trying to do something special, and then a for-on loop is useless anyway.

> Symbol.iterator interface

I get it, but it's unnecessary abstraction to overgeneralize a vanilla array to an iterable.

anyway, for..of is not an issue, it's alright. I think if there's one main point i'm trying to make, is that devs will write objectively worse code base on gut wants (in this case, obsession to use higer level abstractions to iterate over an array).