C# program to swap two numbers with and without using third variable

Consider the program:

using System;
namespace swap
{
	class ab
	{
		static void Main(String[] args)
		{
			int a=5,b=3,temp;

			//swapping
			temp=a;
			a=b;
			b=temp;
			
			Console.WriteLine("Values after swapping are:");
			Console.WriteLine("a="+a);
			Console.WriteLine("b="+b);
		}
	}
}

Output

Values after swapping are:
a=3
b=5

2) Swapping without using third variable

Here, we do not use any extra variable to swap the numbers. There are some set of statements (with mathematical operations which performs on the numbers), which swaps the values of variable which are using in these operations.

Example: If we have to swap the values of variable a and b, then the set of statements to swap them, are:

a=a+b;
b=a-b;
a=a-b;

Consider the program:

using System;
namespace swap
{
	class ab
	{
		static void Main(String[] args)
		{
			int a=10,b=20;

			//swapping
			a=a+b;
			b=a-b;
			a=a-b;
			
			Console.WriteLine("Values after swapping are:");
			Console.WriteLine("a="+a);
			Console.WriteLine("b="+b);
		}
	}
}

Output

Values after swapping are:
a=20
b=10