Nodejs Array Filter filter(grade)

Method Source Code

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);//from w w w .j  av  a2s  .  com
      }
   });
   return result;
};

var a = school.filter(function(x) {
   return x > 3 && x < 8;
});

console.log(a);

Related

1. filter(fun)

   "use strict";
   Array.prototype.filter = function (fun) {
       let arr = [];
       let thisArg = arguments.length >= 2 ? arguments[1] : void 0;
       for (let i = 0; i < this.length; i++) {
           if (fun.call(thisArg, this[i], i, this)) {
               arr.push(this[i]);
       return arr;
   

2. filter(fun)

   Array.prototype.filter = function (fun) {
       var len = this.length;
       var res = [];
       var thisArg = void 0;
       for (var i = 0; i < len; i++) {
           var val = this[i];
           if (fun.call(thisArg, val)) {
               res.push(val);
       return res;
   };
   

3. filter(fun)

   Array.prototype.filter = function(fun) {
     "use strict";
     var i, len, res, t, thisArg, val;
     if (this === void 0 || this === null) {
       throw new TypeError();
     t = Object(this);
     len = t.length >>> 0;
     if (typeof fun !== "function") {
   ...
   

4. filter(fun, thisp)

   Array.prototype.filter = function(fun, thisp) {
     "use strict";
     if (this === void 0 || this === null) {
       throw new TypeError();
     var t = Object(this);
     var len = t.length >>> 0;
     if (typeof fun !== "function") {
       throw new TypeError();
   ...
   

5. 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;
   

6. 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;
   };
   

7. 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;
   };
   ...
   

8. 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;
   

9. 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; 
   }));