largestInMatrix.js

function largestOfFour(arr) {
  var temp = [];
  
  for(var i = 0; i < arr.length; i++){
    
    var elem = arr[i];
    elem.sort(function(a, b){
        return a < b;
      });
    
    temp.push(elem[0]);
  }
  
  arr = temp;
  return arr;
}