http://www.freecodecamp.com/mtroiani 's solution for Bonfire: Mutations

gistfile1.txt

// Bonfire: Mutations
// Author: @mtroiani
// Challenge: http://www.freecodecamp.com/challenges/bonfire-mutations
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function mutation(arr) {
  var target = arr[0];
  target = target.toLowerCase().split('');
  var test = arr[1];
  test = test.toLowerCase().split('');
  for (var i = 0; i < test.length; i ++) {
    if (target.indexOf(test[i]) < 0)
      return false; 
  }
  return true;
  }

mutation(["hello", "hey"]);