creditcard wout comments

   var creditSum = function(creditNumbers) {

  	var max = 0;  // This is the sum of the largest credit card
  	var largestSum; // This represents the string value of the largest credit card. 

  	for(var i = 0; i < creditNumbers.length; i++) {
  		var total = 0;
  		var numberString = creditNumbers[i];


  		for(var j = 0; j < numberString.length; j++) {


 			var singleNumber = parseInt(numberString.charAt(j)); 
 			if(singleNumber) {


  				total += singleNumber;
  			}
  		}   


    		if(total >= max) {
  			max = total;
 

  			largestSum = creditNumbers[i];
  		}   
  	}
  	return largestSum;
  };


  var creditCards = ['4916-2600-1804-0530', '4779-252888-3972', '4252-278893-7978', '4556-4242-9283-2260'];

creditSum(creditCards);


console.log(creditSum(creditCards));
'4252-278893-7978'