Find the index of the longest array in an array of arrays

Question

If you have an array containing an indefinite amount of arrays

ex:

var masterArray = [ [1,2,3,4,5],
                    [1,2], 
                    [1,1,         


        

Answer 1

masterArray.reduce(function(a,i,ii){
  if (ii === 1){
    return a
  };
  if (i.length > a.length){
    return i
  }
  return a
})