Nodejs Utililty Methods Array Item Occurrence

Array.prototype.numberOfOccurrences = function(num) {
    return this.filter(function(item){return item==num;}).length;

Array.prototype.numberOfOccurrences = function (num) {
  var output = 0;
  for (var i=0; i<this.length; i++) {
    if (this[i] === num) {
      output++;
  return output;
};
...

Array.prototype.numberOfOccurrences = function(number) {
  return this.reduce(function (previous, current) {
    return (current === number) ? ++previous : previous;
  }, 0);
};

Array.prototype.numberOfOccurrences = function (search) {
  return this.filter(function (num) { return search === num }).length;

Array.prototype.numberOfOccurrences = function(search) {
  return this.filter( function(num){ return search === num } ).length;

Array.prototype.numberOfOccurrences = function(target) {
  for(var i =0;i<this.length;i++){
    var x = this.filter(function(b){return b === target}).length
  return x;

Array.prototype.numberOfOccurrences = function(val) {
  var count = 0;
  for(var i = 0; i < this.length; i++){
    if(this[i] === val){
      count++;
  return count;

Array.prototype.numberOfOccurrences = function(val) {
  var count = 0;
  for(var i=0;i<this.length;i++){
    if(val === this[i]){
      count += 1;
  return count;

Array.prototype.numberOfOccurrences = function(value) {
  var count = 0;
  this.forEach(function(elem, index){
    if(elem === value){
      count++;
  });
  return count;
};
...

Array.prototype.numberOfOccurrences = function(values) {
var tracker = 0;
    for(var i = 0; i < this.length; i++)
        if (this[i]== values){
            tracker++;
    console.log(tracker);
...