Nodejs Array Filter filter(callback)

Method Source Code

Array.prototype.filter = function(callback){
    const newArr = []//from   w w w .j a  va  2s  .c o m
    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)

Related

1. 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;
   };
   ...
   

2. 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;
   };
   

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;