Nodejs Array Filter filter(callback, context)

Method Source Code

Array.prototype.filter = function(callback, context) {
  let filtered = [];//from  w ww  .  ja v a  2  s .  co  m
  this.forEach((item, index) => {
    if (callback.call(context, item, index, this))
      filtered.push(item);
  });
  return filtered;
};

Related

1. filter(callback)

   Array.prototype.filter = function(callback){
       const newArr = []
       for(let i = 0; i < this.length; i += 1){
           if(callback(this[i])){
               newArr.push(this[i])
       return newArr
   const arr = [1,2,3,4,5,6,7]
   const newArr = arr.filter((value) => {
       return (value%2 === 0)
   })
   console.log(newArr)
   

2. filter(callback)

   Array.prototype.filter = function(callback){
     var a = -1,
       len = this.length,
       result = [];
     while(++a < len){
       callback(this[a], a, this) && result.push(this[a]);
     return result;
   };
   ...
   

3. filter(callback, context)

   var array = [1,2,3,4,5,6,7,8,9,4,5,6,7,7,5,6]
   var arrNew = array.Reject(function (el)
     return el % this
   }, 2)
   console.log(arrNew)
   Array.prototype.filter = function (callback, context)
     var arr = []
   ...
   

4. filter(callbackfn, thisArg)

   Array.prototype.filter = function (callbackfn, thisArg) {
     var xs = [];
     for (var i=0; i<this.length; i++)
       if (Kernel.Reflect.apply(callbackfn, thisArg, [this[i], i, this]))
         xs[xs.length] = this[i];
     return xs;
   

5. filter(cb)

   Array.prototype.filter = function(cb){
       var arr = Object(this);
       var res = [];
       for(var i=0;i<arr.length;i++){
           if(cb(arr[i])){
               res.push(arr[i]);
       return res;
   ...
   

6. filter(f)

   var arr = ['hello', 42, true, function() {}, "123", 3.14, 0, [1], {}];
   var isInteger = function(x) {
       return (typeof x === 'number' && isFinite(x) && Math.floor(x) === x);
   Array.prototype.filter = function(f) {
       var newArr = [];
       for (var i = 0; i < this.length; i++) {
           if (f(this[i])) newArr.push(this[i]);
       return newArr;
   };
   var newArr = arr.filter(isInteger);
   console.log(newArr);