Uniquify array

gistfile1.js

/**
 * @param arr {Array}
 * @returns {Array} a new array of sorted, unique elements of give array.
 */
var uniquify = function (arr) {
  arr.sort();
  var result = [];
  for (var i = 0, len = arr.length; i < len; ++i) {
    if (i === 0) {
      result[result.length] = arr[i];
    }
    else if (arr[i - 1] !== arr[i]) {
      result[result.length] = arr[i];
    }
  }
  return result;
};