1             var arr =[3,5,7,4,2,3,0,5,3];
 2             //console.log(arr.reverse());//数组反序  3,5,0,3,2,4,7,5,3
 3             
 4             function sort(){//去重
 5                 for (var i=0; i < arr.length; i++) {
 6                     for (j = i+1; j < arr.length; j++) {
 7                         if(arr[i]==arr[j]){
 8                             arr.splice(j,1); //删除等于arr[i]的值 ,arr.length会自动减1
 9                         }
10                     }
11                 }
12                 return arr;
13             }
14             //console.log(sort());   //3,5,7,4,2,0
15             function numUp(){ //选择排序
16                 var t;
17                 for (var i=0; i < arr.length; i++) {
18                     for (j = i+1; j < arr.length; j++) {
19                         if(arr[i]>arr[j]){
20                             t = arr[i];    //这3行的目的就是交换 2个数组元素的位置
21                             arr[i]=arr[j];
22                             arr[j] =t;
23                         }
24                     }
25                 }
26                 return arr;
27             }
28             sort();//去重
29             //console.log(numUp()); //0,2,3,4,5,7