function largestOfFour(arr) { var newArray = []; for(var i =0; i <=arr.length-1; i++){ console.log(arr[i]); newArray[i] = Math.max(arr[i]);
Using lodash
var x = ([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]); _.flatten(x).max();