I think there is a mistake in the 1st code which you have provided which is for map() method. Where you have written code for anonymous fn call in the return statement you are multiplying current element of array with 3 so the output would be [ 3, 6, 9, 12, 15 ].
Dumebi Okolo you actually wrote x*3 in the second example. The anotherNumbersArray constant. That's what he's trying to say.