Credit Card Checker: Separation of elements within a nested array

Hi guys,
I’m doing task 4 in the CCC project and got stuck with the display of nested arrays that contain valid and invalid card numbers. In my code these arrays look like if they contain numbers of all appropriate cards as elements without any separation for each card. What should I do to differentiate numbers within one card from numbers of another?
Here is my code:

and here is the outcome:
Invalid cards are;5,7,9,5,5,9,3,3,9,2,1,3,4,6,4,3,3,7,5,7,9,6,0,8,4,4,5,9,9,1,4,5,3,8,2,0,1,9,7,7,2,8,8,3,8,5,4,3,4,4,8,0,1,9,6,8,3,0,5,4,1,4,6,0,1,1,3,7,7,0,2,0,9,6,2,6,5,6,2,0,3,4,9,2,9,8,7,7,1,6,9,2,1,7,0,9,3
Valid cards are;4,5,3,9,6,7,7,9,0,8,0,1,6,8,0,8,5,5,3,5,7,6,6,7,6,8,7,5,1,4,3,9,3,7,1,6,1,2,0,1,9,9,8,5,2,3,6,6,0,1,1,1,4,4,3,4,0,6,8,2,9,0,5,4,5,3,9,4,0,4,9,6,7,8,6,9,6,6,6,4,5,3,2,7,7,8,7,7,1,0,9,1,7,9,5,6,0,1,1,1,2,7,9,6,1,7,7,7,9,3,5,5,4,6,6,1,0,0,8,6,1,6,2,0,2,3,9,4,9,1,3,5,4,0,4,6,3,0,7,2,5,2,3

I’m not 100% sure but I think it has to do with string concatenation with an array. If you were to console.log() newInvalidCards or newValidCards by themselves it should display the arrays the way you want. You could also create your own function to make more customs strings and take advantage of loops and some of the built-in array methods like .join()

1 Like

Thanks, mate! Indeed, if I pass
findInvalidCards(batch);
console.log(newInvalidCards);
the numbers are separated. It’s time to do another review of the theory :slight_smile: