Nodejs Array Item Occurrence numberOfOccurrences(item)

Method Source Code

/*//from w ww.  j av  a 2s  .co m
# Codewars: Number of Occurrences

In this exercise, we are asked to check the occurrence of an array item.

*/

var arr = [4, 0, 4];

Array.prototype.numberOfOccurrences = function(item) {

   tmp = 0;

   for(var i=0; i<this.length; i++){
      if (item == this[i]) {
         tmp ++;
      }
   }

   // return tmp;
   console.log(tmp);

}

arr.numberOfOccurrences(0);
arr.numberOfOccurrences(4);
arr.numberOfOccurrences("a");

Related

1. numberOfOccurrences(desVal)

   Array.prototype.numberOfOccurrences = function(desVal) {
     var counter = 0;
     this.forEach(function(value){
       if(value === desVal){
         counter++;
     });
     return counter;
   };
   ...
   

2. numberOfOccurrences(el)

   Array.prototype.numberOfOccurrences = function (el) {
     var count = 0;
     this.forEach(function (item) {
       if (item === el) count++;
     });
     return count;
   

3. numberOfOccurrences(elem)

   Array.prototype.numberOfOccurrences = function(elem) {
     let obj = {};
     this.forEach(elem => elem in obj ? obj[elem]++ : obj[elem] = 1);
     return obj[elem] === undefined ? 0 : obj[elem]
   

4. numberOfOccurrences(i)

   Array.prototype.numberOfOccurrences = function(i) {
     var total = 0;
     this.filter(function (x) {
       if (i === x)
         total++;
     });
     return total;
   };
   var arr = [0,1,2,2,3];
   ...
   

5. numberOfOccurrences(item)

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

6. numberOfOccurrences(n)

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

7. numberOfOccurrences(num)

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

8. numberOfOccurrences(num)

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

9. numberOfOccurrences(number)

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