class BoxPointer {

  Counter c1;
  Counter c2;

  public void swap(Counter x1, Counter x2) {
    Counter temp = x1;
    x1 = x2;
    x2 = temp;
  } // End swap()

  public void swap1(Counter x1, Counter x2) {
    Counter temp = x1;
    x1 = x2;
    x2 = temp;
    c1 = x1;
    c2 = x2;
  } // End swap1()

  public void swap2(Counter x1, Counter x2) {
    int temp = x1.x;
    x1.x = x2.x;
    x2.x = temp;
  } // End swap2()

  public void swap3() {
    Counter temp = c1;
    c1 = c2;
    c2 = temp;
  } // End swap3()

  public void swap4_int(int a, int b) {
    int temp = a;
    a = b;
    b = temp;
  }

  public void swap5_array_elements(int[] B, int i, int j) {
    int temp = B[i];
    B[i] = B[j];
    B[j] = temp;
  }

  public static void main(String[] args) {
    BoxPointer bp = new BoxPointer();
    bp.c1 = new Counter();
    bp.c2 = new Counter();
    bp.c2.increment();
    //bp.swap(bp.c1, bp.c2);
    //bp.swap1(bp.c1, bp.c2);
    bp.swap2(bp.c1, bp.c2);

    System.out.println("        c1 is "+bp.c1.getCurrentValue());
    System.out.println("        c2 is "+bp.c2.getCurrentValue());

    int x = 5;
    int y = 10;
    bp.swap4_int(x, y);
    System.out.println("        x is " + x);
    System.out.println("        y is " + y);

    int A[] = new int[10];
    A[0] = 5;
    A[1] = 10;
    //bp.swap4_int(A[0], A[1]);
    bp.swap5_array_elements(A, 0, 1);
    System.out.println("        A[0] is " + A[0]);
    System.out.println("        A[1] is " + A[1]);

  } // End main()

} // End class BoxPointer