Nodejs Array Filter filter(fun)

Method Source Code

"use strict";//  w ww  . j a  va2s .  co m

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;
};

console.log([1, 2, 3, 4].filter((num)=> {
    return num > 3
}));

Related

1. filter(fn)

   Array.prototype.filter = function(fn)
       r = [];
       this.forEach(function (item) { if (fn(item)) r.push(item); });
       return r;
   

2. filter(fn, context)

   Array.prototype.filter = function(fn, context) {
     if (typeof fn != "function") {
       throw new TypeError(fn + " is not a function");
     if (typeof context === 'undefined') {
       context = this;
     var res = [];
     for (var i = 0, l = this.length; i < l; ++i) {
   ...
   

3. 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;
   ...
   

4. 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++) {
   ...
   

5. 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) {
   ...
   

6. 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;
   

7. 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;
   };
   

8. 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") {
   ...
   

9. 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();
   ...