/* Call by reference */

import java.io.*;

class swap {
	int i, j;

	/* Constructor */
	swap(int a, int b) {
		int c;

		/* Swapping Values */
		c = a;
		a = b;
		b = c;
		i = a;
		j = b;
	}
}

class callbyref {
	public static void main(String args[ ]) {
		int x = Integer.parseInt(args[0]);
		int y = Integer.parseInt(args[1]);
		swap swp = new swap(x, y);
		System.out.println("Before Swapping");
		System.out.println("x = "+x+"\ny = "+y.j);
		System.out.println("After Swapping");
		System.out.println("x = "+swp.i+"\ny = "+swp.j);
	}
}


          /****** Output ******/
          
java callbyref 4 8

Before Swapping

x = 4

y = 8

After Swapping

x = 8

y = 4