Credit Card Checker: Solution

Here is my solution for the credit checker project on the javascript course.
Feedback is highly appreciated.

Hi and thanks for sharing your solutions. I gained some insight on how to apply the array functions and methods to this program. I am just a bit confused as to why all of the digits were doubled. I understood the instructions to state that every other digits from the right should be doubled. Does [every other] mean to skip one digit in the iteration? For instance (i-2). Thanks for your assistance