defaultCompareFunction = function defaultCompareFunction(a, b) {
  // sort lexically
  var firstValue = a.toString();
  var secondValue = b.toString();

  if (firstValue === secondValue) {
    return 0;
  } else if (firstValue < secondValue) {
    return -1;
  }

  return 1;
}
Specifies a function that defines the sort order. The array is sorted according to each
character's Unicode code point value, according to the string conversion of each element.

@param a {*} first compared element.
@param b {*} second compared element.
@returns {Number}