Nodejs Array Item Occurrence numberOfOccurrences(val)

Method Source Code

/*//w  w  w .ja  v  a 2 s.com
Description:

The numberOfOccurrences function must return the number of occurrences of an element in an array.

var arr = [0,1,2,2,3];
arr.numberOfOccurrences(0) === 1;
arr.numberOfOccurrences(4) === 0;
arr.numberOfOccurrences(2) === 2;
arr.numberOfOccurrences("a") === 0;

*/

///Solution///

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

Related

1. numberOfOccurrences(number)

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

2. numberOfOccurrences(search)

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

3. numberOfOccurrences(search)

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

4. numberOfOccurrences(target)

   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;
   

5. numberOfOccurrences(val)

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

6. numberOfOccurrences(value)

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

7. numberOfOccurrences(values)

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