js的几种简单排序算法及其效率实测

 function swap(arr,index1,index2){

     var t = arr[index1];

     arr[index1] = arr[index2];

     arr[index2] = t;

 }

 function Sarray(num){

     this.nums = [];

     this.num = num;

 }

 Sarray.prototype.init = function() {

     for (i=0;i<this.num;i++){

         this.nums.push(Math.floor(Math.random()*(this.num+1)));

     }

 };

 Sarray.prototype.bubbleSort = function(){

     for (var i=this.nums.length;i>1;i--){

         for (var j=0;j<i;j++){

             if(this.nums[j]>this.nums[j+1]){

                 swap(this.nums,j,j+1);

             }

         }

     }

 }

 Sarray.prototype.selectionSort = function(){

     for (var i=0;i<this.nums.length-1;i++){

         var min = i;

         for (var j=i+1;j<this.nums.length;j++){

             if(this.nums[min]>this.nums[j]){

                 min = j;

             }

         }

         if(min!=i){

                 swap(this.nums,i,min);

             }

     }

 }

 Sarray.prototype.insertSort = function(){//默认0号位置有序

     for (var i=1;i<this.nums.length;i++){

         var tem = this.nums[i];

         var j = i;

         while(this.nums[j-1]>tem&&j>0){

             this.nums[j] = this.nums[j-1];

             j--;

         }

         this.nums[j] = tem;

     }

 }

 var n=10000;

 var a = new Sarray(n);

 var b = new Sarray(n);

 var c = new Sarray(n);

 a.init();

 b.init();

 c.init();

 var start = new Date().getTime();

 a.bubbleSort();

 var end = new Date().getTime();

 console.log("冒泡排序用时:"+(end-start)+"ms");

 start = new Date().getTime();

 b.selectionSort();

 end = new Date().getTime();

 console.log("选择排序用时:"+(end-start)+"ms");

 start = new Date().getTime();

 c.insertSort();

 end = new Date().getTime();

 console.log("插入排序用时:"+(end-start)+"ms");