reverse array

 1 public static void main(String[] args) {
 2         int[] org = {2,3,8,4,1 } ;
 3         int[] res = reverseArray(org);
 4         print(res);
 5     }
 6 
 7     //用一次遍历，一个指针完成 2,3,8,4,1 -> 1,4,8,3,2
 8     private static int[] reverseArray(int[] org) {
 9         int[] res = new int[org.length] ;
10         int j = org.length -1 ; // reverse index
11         for (int i = 0; i < org.length ; i++) {
12             res[j--] = org[i] ;
13         }
14         return res ;
15     }
16     private static void print(int[] arr){
17         for (int i = 0; i <arr.length ; i++) {
18             System.out.println(arr[i]);
19         }
20     }