Nodejs Array Filter filter(predicate)

Method Source Code

Array.prototype.filter = function (predicate) {
    let result = [];// w  w w .j a  va2  s.  c  o  m

    this.forEach(item => {
        if (predicate(item)) {
            result.push(item);
        }
    })

    return result;
};

Related

1. 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;
   ...
   

2. 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;
   };
   

3. 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;
   };
   ...
   

4. 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;
   

5. filter(predicate)

   Array.prototype.filter = function(predicate){
     return this.reduce(function(accumulator, value){
       return predicate(value) ? accumulator.concat(value) : accumulator;
     }, []);
   console.log([1, 2, 3, 4, 5].filter(function(val){
     return val % 2 === 0; 
   }));
   

6. 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;
   

7. filter(predicateFunction)

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

8. filter(predicateFunction)

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

9. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction){
     var result = [];
     this.forEach(function(item){
       if(predicateFunction(item)) {
         result.push(item);
     })
     return result;
   Array.prototype.map = function(predicateFunction){
     var result = [];
     this.forEach(function(item){
       result.push(predicateFunction(item));
     })
     return result;
   var a = [1,2,3,4,5,6,7,8,9];
   a.map(function(x){
     return x*2;
   }).filter(function(x){
     if(x > 4) return true;
   })