public class TestSwapArrayInt {

    public static void swap(int[] xs) {

        int[] ys;
        ys = new int[2];

        ys[0] = xs[1];
        ys[1] = xs[0];
                
        xs = ys;

    }
        
    public static void main(String[] args) {

        int[] xs;
        xs = new int[2];

        xs[0] = 15;
        xs[1] = 21;

        swap(xs);

        System.out.println(xs[0]);
        System.out.println(xs[1]);

    }
}