Nodejs Utililty Methods Array Extend

Array.prototype.extend = function()
  var oCurrentObj = {};
  for(var i = 0; i < this.length; i++)
    oCurrentObj = this[i].extend(oCurrentObj);
  return oCurrentObj;

Array.prototype.extend = function(arr) {
    this.push.apply(this, arr);
    return this;

Array.prototype.extend = function(array)
    this.push.apply(this, array)

Array.prototype.extend = function(array){
  for (var j = array.length-1; j >= 0; j--) this.unshift(array[j]);
  return this;
};

Array.prototype.extend = function(array) {
  for (var i = 0; i < array.length; i++) {
    this.push(array[i]);

Array.prototype.extend = function (newItems) {
    return this.push.apply(this, newItems);
};

Array.prototype.extend = function (other) {
  other.forEach(function(v) {this.push(v)}, this);    
};

Array.prototype.extend = function(other_array) {
    other_array.forEach(function(v) {
        this.push(v)
    }, this);

Array.prototype.extend = function(other_array) {
  if(other_array.constructor !== Array) throw other_array + ' is not an array.';
  other_array.forEach(function(v) {
    this.push(v)
  }, this);

Array.prototype.extend = function(source) {
  for (var attr in source) {
    if (Object.prototype.toString.call(source[attr]).slice(8, -1).toLowerCase() === 'array') {
      this[attr] = [];
      this[attr].extend(source[attr]);
    } else {
      this[attr] = source[attr];