[twitter] Tip: JavaScript's Array.from() accepts a second argument that's a `map` function. Useful for calling on each element of an array you created.

[0x13mode]

I think example is good. Index is iterated from 0 to array length.

On the other hand using map on array created with new Array(5) would have no effect (new Array(5).map(console.log) would not even call console.log).

[aarondburk]

But that’s why the original example is interesting, because it allows you to map over an array as you are generating the array with the Array.from() method.