Nodejs Utililty Methods Array Sum

Array.prototype.sum = function () {
  var sum = 0;
  for (var i = 0; i < this.length; i++) {
    sum += this[i];
  };
  return sum;
console.log([1, 3, 12, 33, 2].sum());

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

const assert = require('assert')
Array.prototype.sum = function() {
  return this.reduce((sum, el) => sum + el, 0)
assert.equal([].sum(), 0)
assert.equal([2, 5, 7].sum(), 14)

Array.prototype.sum = function() {
    var res = 0;
    for(var p in this)
  res += this[p];
    return res;
};
var a = [1, 2, 3];
var all_in = true;
for(var i=0;i<5;++i)
...

var ary1 = new Array(12, 55, 43, 32, 44);
var ary2 = new Array(12, 33, 1);
Array.prototype.sum = function() {
    var output = 0;
    for (var i = 0; i < this.length; i++) {
        output += this[i];
    return output;
};
...

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

var numbers = [1,2,3,4,5,6];
Array.prototype.sum = function(){
  return this.reduce(function(p, c){
    return p+c;
  })
var result = numbers.sum();
console.log(result);
console.log(numbers);
...

Array.prototype.sum = function(){
  for(var i=0,sum=0;i<this.length;sum+=this[i++]);
  return sum;
Array.prototype.max = function(){
  return Math.max.apply({},this)
Array.prototype.min = function(){
  return Math.min.apply({},this)
...

Array.prototype.sum = function() {
  var i;
  var s:Number = 0;
  for (i=0; i < this.length; i++) {
    s += Number(this[i]);
  return s;
var test = new Array(1, 2, 3);
...

'use strict';
Array.prototype.sum = function () {
    var total = 0;
    var i = this.length;
    while (i--) {
        total += this[i];
    return total;
};
...