Nodejs Array Filter filter(f)

Method Source Code

// complete the following such that a new array with only integers
// (while numbers) is returned

var arr = ['hello', 42, true, function() {}, "123", 3.14, 0, [1], {}];

var isInteger = function(x) {
    return typeof x === 'number' && !isNaN(x) && x % 1 === 0;
};

Array.prototype.filter = function(f) {
    var newArr = [];

    for (var i = 0; i < this.length; i++) {
        if ( f(this[i]) ) {
            newArr.push(this[i]);//from  w ww . jav  a  2s.  c o m
        }
    }
    return newArr;
};

var newArr = arr.filter(isInteger);
console.log(newArr);

Related

1. filter(callback, context)

   Array.prototype.filter = function(callback, context) {
     let filtered = [];
     this.forEach((item, index) => {
       if (callback.call(context, item, index, this))
         filtered.push(item);
     });
     return filtered;
   };
   

2. 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 = []
   ...
   

3. 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;
   

4. 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;
   ...
   

5. 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);
   

6. filter(f)

   Array.prototype.filter = Array.prototype.filter || function (f) {
     var result = [];
     this.each(function (element) {
       if (f(element, result.length)) {
         result.push(element);
     });
     return result;
   };
   ...
   

7. filter(f)

   Array.prototype.filter = function(f) {
     var filtered = [];
       for(var i = 0; i < this.length; i++)
         f(this[i], i) && filtered.push(this[i]);
       return filtered;
   };
   

8. filter(f)

   Array.prototype.filter = function(f) {
     var filter = [];
     for (var i = 0; i < this.length; i++) {
       if (f(this[i]))
         filter.push(this[i]);
     return filter;
   };
   

9. filter(filterFunc)

   Array.prototype.filter = function(filterFunc) {
     var ret = [];
     for(var i = 0; i < this.length; i++) {
       if(filterFunc(this[i])) {
         ret.push(this[i]);
     return ret;
   };
   ...