Performance aside, also consider Ramda.js

Although Ramda has forEach, I augment it with a version of each(func, data) where data can be an array or map, and func(val, key) where key is the key of the map item, or the index of the item in the array.

I feel this abuse of notation makes for more readable / smaller / uniform code [ having no explicit for loops ]. Also takes less conceptual space.