Why do we use `Number.prototype.valueOf` inside of a `map()` function

Question

The following code:

let resultsArray = Array.apply(null, Array(10)).map(Number.prototype.valueOf,0);

creates the following array

Answer 1

There is another solution

Array.from(new Array(10), () => 0)

Ad if your browser does not support ES6, then

Array.from(new Array(10), function(){return 0;})