Nodejs Array Reduce _reduce(f)

Method Source Code

Array.prototype._reduce = function(f){
    let acc = this[0];//from w w  w  .  ja  va  2  s  .co m
    for(let i = 1; i < this.length; i++){
        acc = f(acc,this[i])
    }
    return acc;
}

Related

1. reduce(testFunction,initialValue)

   Array.prototype.reduce = function(testFunction,initialValue){
     var accumulatedValue,counter;
     if(this.length == 0){
       return this;
     }else{
       if(arguments.length == 1){
         counter = 1;
         accumulatedValue = this[0];
       }else if(arguments.length >= 2){
   ...
   

2. reduce.call(str, (trav, char)>

   'use strict';
   class PrefixTree {
       constructor() {
           this.root = {};
       insert(str) {
           Array.prototype.reduce.call(str, (trav, char) => {
               if (!trav[char]) {
                   trav[char] = {};
   ...
   

3. reduceRight(aggregate, initial)

   Array.prototype.reduceRight = function(aggregate, initial) {
     const len = this.length;
     let startIndex = len - 1;
     if(typeof initial === 'undefined') {
       initial = this[0];
       startIndex = len - 2;
     for(let i = startIndex; i >= 0; i -= 1) {
       initial = aggregate(initial, this[i], i, this);
   ...
   

4. reduceRight(fun /*, initial*/)

   Array.prototype.reduceRight = function(fun ) {
       var len = this.length >>> 0;
       if (typeof fun != "function") {
           throw new TypeError();
       if (len == 0 && arguments.length == 1) {
           throw new TypeError();
       var i = len - 1;
   ...
   

5. reduceRight2(pasteback, initial)

   Array.prototype.reduceRight2 = function(pasteback, initial){
     for(var i = this.length
         , value = arguments.length>1 ? initial : this[--i]
     ; i--;){
       value = pasteback(value, this[i], i, this);
     return value;
   };