Javascript Array last(n)

/*//from   ww  w.j a  va 2 s  .  co  m
    Return last n set of elements in an array
*/

Array.prototype.last = function (n) {
    'use strict';
    return this.slice(this.length - (n || 1), this.length);
};

// Returns the last element of an array.
// Passing n will return the last n elements of the array.

var array = [5, 4, 3, 2, 1];

Array.prototype._last = function(n){
  n = n || 1;/*from  w  ww  . jav a  2 s .  c o  m*/
  return this.slice(-n);
};

array._last();
// [1]

array._last(3);
// [3, 2, 1]