credit card sum

app.js

/**
 * Created by joseph on 6/6/16.
 */

function printNumbers(arrayOfCards) {

	var reducedCards = [];

	// iterate over array of cards that was passed to function
	arrayOfCards.forEach(function(card){

		card = card.replace(/-/g, '')
			.split('')
			.reduce(function(prev, curr){
				return Number(prev) + Number(curr);
			});

		reducedCards.push(card);
	});

	return arrayOfCards[reducedCards.lastIndexOf(Math.max.apply(Math, reducedCards))];
}
console.log(printNumbers(['4916-2600-1804-0530', '4779-252888-3972', '4252-278893-7978', '4556-4242-9283-2260']));
console.log(printNumbers(['22-22', '99-90', '99-88', '79-99', '12-34']));
console.log(printNumbers(['22-22', '99-90', '79-99', '99-88', '12-34']));