Swapping of Variables without using Third Variable in Java

// Swapping example without third variable
class SwapWithoutThirdVariable
{
public static void main( String args[ ] )
{
 int   a, b;
 a = 10;
 b = 20;
 System.out.print("\nBefore Swapping : " );
 System.out.print( a + "   " + b );
 a = a + b;
 b = a - b;
 a = a - b;
 
 System.out.print( "\nAfter Swapping  : " );
 System.out.print( a + "   " + b );
}
}

Output:
Before Swapping :  10 20
After Swapping  : 20 10