Nodejs Utililty Methods Array Repeat

Array.prototype.repeat = function(num) {
  var self = this;
  for (var i = 0; i < num; i++) {
    self = self.concat(self);
  return self;
var arr = [1, 2, 3];
var ary = arr.repeat(1);
...

Array.prototype.repeat = function(reps) {
  var copy = this.clone()
  for (var i = 0; i < reps; i++) copy.push.apply(copy, copy)
  return copy

Array.prototype.repeat_element = function(element)
     var repeat = false;
     for (i=0;i<this.length;i++)
         if(element==this[i])
             repeat = true;
     return repeat;
...