How to reverse an array without using any built in method and any other array.

public class ArraySorting
{
    public static void main(String args[]) 
    {
        int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        int n1 = 0, n2 = a.length - 1;
        int temp = 0;
        while (n1 != n2 || n1 < n2) 
        {
            temp = a[n1];
            a[n1] = a[n2];
            a[n2] = temp;
            n1++;
            n2--;
        }
        for (int i = 0; i < a.length; i++) 
        {
            System.out.print(a[i] + " ");
        }
    }
}

Output:

9 8 7 6 5 4 3 2 1 

BUILD SUCCESSFUL (total time: 0 seconds)