Nodejs Array Filter filter(fun)

Method Source Code

// Implement a Filter function
// https://www.codewars.com/kata/implement-a-filter-function

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);//ww  w  .j  a  v a 2s  .  com
        }
    }
    return res;
};

Related

1. filter(fun /*, thisArg */)

   "use strict";
   Array.isArray = function(arg) {
       return Object.prototype.toString.call(arg) === '[object Array]';
   };
   Array.prototype.filter = function(fun ) {
       if (this === void 0 || this === null)
           throw new TypeError();
       var t = Object(this);
       var len = t.length >>> 0;
   ...
   

2. filter(fun /*, thisp */)

   Array.prototype.filter = Array.prototype.filter || function(fun ) {
     "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();
     var res = [];
     var thisp = arguments[1];
     for (var i = 0; i < len; i++) {
   ...
   

3. filter(fun /*, thisp*/)

   Array.prototype.filter = Array.prototype.filter || function(fun ) {
       var len = this.length >>> 0;
       if (typeof fun != "function") {
           throw new TypeError();
       var res = new Array();
       var thisp = arguments[1];
       for (var i = 0; i < len; i++) {
           if (i in this) {
   ...
   

4. filter(fun)

   "use strict";
   Array.prototype.filter = function (fun) {
       let filtered = [];
       for (let i = 0; i < this.length; i++) {
           if (fun(this[i])) {
               filtered.push(this[i]);
       return filtered;
   ...
   

5. 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;
   

6. 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") {
   ...
   

7. 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();
   ...
   

8. 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;
   

9. 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;
   ...