Nodejs Array Merge Sort mergeSort()

Here you can find the source of mergeSort()

Method Source Code

// Monkey Patch merge_sort onto the array class

Array.prototype.mergeSort = function () {

  if ( this.length < 2 ) {
    return this;/*from  w ww  . j  a  v a 2 s . c  om*/
  }

  var mid_idx = Math.floor( this.length / 2 )

  var left = this.slice(0,mid_idx).mergeSort();
  var right = this.slice(mid_idx).mergeSort();

  return merge(left, right);
}

function merge(left, right) {

  var result = [];

    while (left.length > 0 && right.length > 0) {
      var nextItem = (left[0] < right[0]) ? left.shift() : right.shift();
      result.push(nextItem);
    }

  return result.concat(left).concat(right);

}

console.log();
console.log( JSON.stringify( [].mergeSort() ) == JSON.stringify( [] )  );
console.log( JSON.stringify( [6,5,3,1,8,7,2,4].mergeSort() ) == JSON.stringify( [1,2,3,4,5,6,7,8] ) );
console.log();

Related

  1. mergeSort()
    Array.prototype.mergeSort = function(){
        var merge = function(left,right){
            var merged = [];
            while(left.length && right.length){
                merged.push(left[0] <= right[0] ? left.shift():right.shift());
            return merged.concat(left.concat(right));
        if (this.length < 2) return this;
    ...
    
  2. mergeSort()
    Array.prototype.mergeSort = function(){
        var merge = function(left,right){
            var merged = [];
            while(left.length && right.length){
                merged.push(left[0] <= right[0] ? left.shift():right.shift());
            return merged.concat(left.concat(right));
        var myarray = [];
    ...
    
  3. mergeSort()
    Array.prototype.mergeSort = function() {
      function merge(left, right) {
        var arr = []
        while(left.length && right.length) {
          if(left[0] < right[0]) {
            arr.push(left.shift())
          } else {
            arr.push(right.shift())
        return arr.concat(left, right)
      var len = this.length
      if(len > 1) {
        var index = Math.floor(len/2)
        var left = this.slice(0, index)
        var right = this.slice(index)
        return merge(left.mergeSort(), right.mergeSort())
      } else {
        return this
    
  4. mergeSort()
    Array.prototype.mergeSort = function () {
      if (this.length <= 1) {
        return this;
      var half = parseInt(this.length / 2);
      var left = this.slice(0, half).mergeSort();
      var right = this.slice(half, this.length).mergeSort();
      var merge = function (left, right) {
      var ary = [];
    ...
    
  5. mergeSort()
    Array.prototype.mergeSort = function () {  
      if (this.length <= 1)   
        return this;  
      var half = parseInt(this.length / 2);  
      var left = this.slice(0, half).mergeSort();  
      var right = this.slice(half,this.length).mergeSort();  
      var merge = function (left, right)   
    ...
    
  6. mergeSort()
    ;"use strict";
    var log=function(msg){console.log(msg);};
    var alert=function(msg){log(msg);};
    var arr = [3,6,7,5,3,6,2,9,1,5,33,-12,0,-122,-Infinity, 125, 33, 55, 77];
    Array.prototype.mergeSort = function () {
      function _merge(arrLeft, arrRight){
          var result = [],
          leftIdx = 0,
          rightIdx = 0;
    ...
    
  7. mergeSort()
    Array.prototype.mergeSort = function() {
        function sort(array) {
            var length = array.length,
                mid    = Math.floor(length * 0.5),
                left   = array.slice(0, mid),
                right  = array.slice(mid, length);
            if(length === 1) {
              return array;
            return merge(sort(left), sort(right));
        function merge(left, right) {
            var result = []
            for (var li=0,ri=0,i=0;i<left.length+right.length;i++){
                if (li < left.length && ri < right.length) {
                    if (less(left[li], right[ri])) {
                        result[i]=left[li]
                        li++
                        continue
                    else {
                        result[i]=right[ri]
                        ri++
                        continue
                if (li===left.length) {
                    result[i]=right[ri]
                    ri++
                    continue
                else {
                    result[i]=left[li]
                    li++
                    continue
            virtualize(result, 0)
            return result
        var newArray=sort(this)
        return newArray
    
  8. mergeSort()
    Array.prototype.mergeSort = function() {
        function sort(array) {
            var length = array.length,
                mid    = Math.floor(length * 0.5),
                left   = array.slice(0, mid),
                right  = array.slice(mid, length);
            if(length === 1) {
              return array;
            return merge(sort(left), sort(right));
        function merge(left, right) {
            var result = []
            for (var li=0,ri=0,i=0;i<left.length+right.length;i++){
                if (li < left.length && ri < right.length) {
                    if (less(left[li], right[ri])) {
                        result[i]=left[li]
                        li++
                        continue
                    else {
                        result[i]=right[ri]
                        ri++
                        continue
                if (li===left.length) {
                    result[i]=right[ri]
                    ri++
                    continue
                else {
                    result[i]=left[li]
                    li++
                    continue
            return result
        var newArray=sort(this)
        return newArray
    
  9. mergeSort(arr2, arr3)
    Array.prototype.mergeSort = function(arr2, arr3) {
      return this.merge2way(arr2.merge2way(arr3));
    var maxNumber = process.argv[2];
    function getRandomArbitrary(min, max) {
      return Math.round(Math.random() * (max - min) + min);
    var arr1 = [getRandomArbitrary(1, 5)],
      arr2 = [getRandomArbitrary(1, 5)],
    ...