Nodejs Array Filter filter(predicate)

Method Source Code

Array.prototype.filter = function(predicate){
   return this.reduce(function(accumulator, value){
      return predicate(value) ? accumulator.concat(value) : accumulator;
   }, []);//  w ww  . java 2  s.  c  o  m
}

console.log([1, 2, 3, 4, 5].filter(function(val){
   return val % 2 === 0; 
}));

//console.log([1, 2, 3, [4, 5, 6], [7, 8, [9, 10, [11, 12]]], 13 ].flatten())

Related

1. filter(func)

   Array.prototype.filter = function(func) {
       var result = [];
       for(var i=0;i<this.length;i++) 
           if (func(this[i]))
               result.push(this[i]);
       return result;
   

2. filter(grade)

   var school = [1, 2, 3, 4, 5, 6, 7, 8, 3, 35, 3, 5];
   Array.prototype.filter = function(grade) {
     var result = [];
     this.forEach(function(item) {
       if (grade(item)) {
         result.push(item);
     });
     return result;
   ...
   

3. filter(isOk)

   const array = [1, 42, 7, 9, 13, 10, 20, 35, 45, -7, -3, 0, 4, -1, 15];
   Array.prototype.filter = function (isOk) {
     let filteredArray = [];
     const len = this.length;
     for (let i = 0; i < len; i += 1) {
       if(isOk(this[i], i, this)) {
         filteredArray.push(this[i]);
     return filteredArray;
   };
   

4. filter(iterator)

   Array.prototype.filter = function(iterator) {
     var results = [];
     for (var i = 0, len = this.length; i < len; i++) {
       if (iterator(this[i], i)) {
         results.push(this[i]);
     return results;
   };
   ...
   

5. filter(predicate)

   Array.prototype.filter = function(predicate) {
     var result = []
     for ( var i = 0; i < this.length; i++) {
       if (predicate(this[i])) {
         result.push(this[i]);
     return result;
   

6. filter(predicate)

   Array.prototype.filter = function (predicate) {
       let result = [];
       this.forEach(item => {
           if (predicate(item)) {
               result.push(item);
       })
       return result;
   };
   ...
   

7. filter(predicate)

   Array.prototype.filter = function(predicate) {
     var filtered_array = [];
     this.forEach(function (element, i) {
       if (predicate(element)) filtered_array.push(element);
     });
     return filtered_array;
   

8. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if (predicateFunction(itemInArray)) {
       results.push(itemInArray);
     });
     return results;
   };
   ...
   

9. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if(predicateFunction(itemInArray) == true)
         results.push(itemInArray);
     });
     return results;
   };