How to swap two numbers without using temporary variable?

Description:

Write a program to swap or exchange two numbers. You should not use any temporary or third variable to swap.

Code:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 package com.govindsblog.algos;   public class MySwapingTwoNumbers {       public static void main(String a[]){         int x = 10;         int y = 20;         System.out.println("Before swap:");         System.out.println("x value: "+x);         System.out.println("y value: "+y);         x = x+y;         y=x-y;         x=x-y;         System.out.println("After swap:");         System.out.println("x value: "+x);         System.out.println("y value: "+y);     } }

Output:

Before swap: x value: 10 y value: 20 After swap: x value: 20 y value: 10