Nodejs Array Value iReduce(handler, initialValue)

Method Source Code

var ary = [0,1,2,3,4,5,6,7,8,9];
var initialValue;

Array.prototype.iReduce = function(handler, initialValue) {
   if (typeof handler !== 'function') {
      throw new Error(handler + 'is not a function!');
   }/*w w w .ja  v  a2 s  .co m*/
   var ary = this;
   var i = 0;
   var tempCurrent = initialValue;
   // ??initialValue,?????
   if (arguments.length === 1) {
      i = 1;
      tempCurrent = ary[0];
   }

   for (; i<ary.length; i++) {
      tempCurrent = handler(tempCurrent, ary[i], i, ary);
   }
   return tempCurrent;
}

var newAry = ary.iReduce(function(previous, current, index, ary) {
   console.log(previous, current, index, ary);
   //console.log(this);
   //console.log('======================');
   return previous + current;
}, initialValue);
console.log(newAry);

Related

1. defaultIfEmpty(val)

   Array.prototype.defaultIfEmpty = function (val) {
     return this.length == 0 ? [val == null ? null : val] : this;
   };
   

2. elementWithAttr(attr, value)

   Array.prototype.elementWithAttr = function (attr, value) {
       for(var i = 0; i < this.length; i += 1) {
           if(this[i][attr] === value) {
               return this[i];
       return null;
   };
   

3. first(attribut, value)

   Array.prototype.first = function (attribut, value) {
       for (var i = 0; i < this.length; i++) {
           if (this[i][attribut] == value)
               return this.slice(i, i + 1)[0];
       return null;
   };
   

4. getNextValue(index)

   Array.prototype.getNextValue = function(index) {
     let nextIndex = index + 1;
     if(nextIndex < this.length) {
       return this[nextIndex];
     return null;
   

5. hasWhere(property, value)

   Array.prototype.hasWhere = function (property, value) {
       "use strict";
       for(var i = 0; i < this.length; i++) {
           if(this[i][property] === value) {
               return true;
       return false;
   };
   ...
   

6. makeArray(value){

   Array.makeArray = function(value){
     if ( !value ) return [];
     if ( typeof value == "string" ) return [value];
     return Array.prototype.slice.call(value, 0);
   };
   

7. nIndexOf(value)

   Array.prototype.nIndexOf = function(value){
       var firstIndex = 0,
           lastIndex = this.length - 1,
           middleIndex = Math.floor((lastIndex + firstIndex) / 2);
       while (this[middleIndex] != value && firstIndex < lastIndex) {
           if (value < this[middleIndex]) {
               lastIndex = middleIndex - 1;
           } else if (value > this[middleIndex]) {
               firstIndex = middleIndex + 1;
   ...
   

8. oneValue()

   Array.prototype.oneValue = function()
       var max = this[0];
       for(el in this)
           if(this[el] !== max && !isNaN(this[el]))
               return false;
       return true;
   };
   

9. pad(minSize, val)

   Array.prototype.pad = function(minSize, val) {
       var padded = new Array();
       for (var i = 0; i < this.length; i++) {
           padded.push(this[i]);
       while (padded.length < minSize) {
           padded.push(val || null);
       return padded;
   ...