for-in vs Object.keys forEach without inherited properties

Question

I was looking at a perf benchmark of Object.keys + forEach vs for-in with normal objects.

This benchmark shows that Obj

Answer 1

And for the ES6 fans out there, looks like

Object.keys(obj).reduce((a,k) => {a += obj[k]; return a}, res)

is by far the fastest.

https://jsperf.com/for-in-vs-for-of-keys-vs-keys-reduce