Nodejs Utililty Methods Array Get Max

Array.prototype.getMAX = function(){
  var max = this[0];
  for(var i = 1; i < this.length; i++){
    if(this[i] > max){
      max = this[i];  
  return max;
var array = new Array();
array[0] = 12;
array.push(12,34,56,78,21,53,10);
document.write(array.getMAX());

Array.prototype.getMax = function() {
  var max = this[0];
  for (var x = 1; x < this.length; x++) {
    if (this[x] > max) {
      max = this[x];
  return max;
};
...

Array.prototype.getMax = function(){
  var temp = 0;
  for(var x=1; x<this.length; x++){
    if(this[x]>this[temp]){
      temp = x;
  return this[temp];

Array.prototype.getMax = function(){
    var arr = this;
    var maxN = arr[0];
    for(var ar in arr){
        if(arr[ar] >= maxN){
            maxN = arr[ar];
    return maxN;
...

Array.prototype.getMax=function(){
  var max=0;
  for(var i=0;i<this.length;i++){
    max=this[i]>max?this[i]:max;
  return max;

var arr = [72, 23,90, 354, 3, 10]
Array.prototype.getMaxNumber = function() {
  var max = this[0]
  this.map(function(value){
    max = Math.max(max, value)
  })
  return max
Array.prototype.getMinNumber = function() {
...