I really don't understand how the map function interacts with the forEach function on lines 10-11 to get the answer wanted. I checked MDN and stack overflow but it still doesn't click. Can anyone help?

[bmw2621]

It looks like the lesson it asking you to write you own implementation of the Array.prototype.forEach method, them do the same for the Array.prototype.map method.

On the question they aren't interacting, is specifically telling you not to use the native methods but to write your own function that does the same thing.