Diff two arrays

index.js

/*
Compare two arrays and return a new array with any items only found in one of the two given arrays, but not both. 
In other words, return the symmetric difference of the two arrays.

*/

function diffArray(arr1, arr2) {
  var newArr = [];

  function check(first, second) {
    for (var i = 0; i < first.length; i++) {
      if (second.indexOf(first[i]) === -1) {
        newArr.push(first[i]);
      }
    }
  }

  check(arr1, arr2);
  check(arr2, arr1);

  return newArr;
}