Swap two variables without using a temporary varia

Question

I'd like to be able to swap two variables without the use of a temporary variable in C#. Can this be done?

decimal startAngle = Convert.ToDecimal(159.9);
decimal stopAngle = Convert.ToDecimal(355.87);

// Swap each:
//   startAngle becomes: 355.87
//   stopAngle becomes: 159.9

Answer 1

we can do that by doing a simple trick

a = 20;
b = 30;
a = a+b; // add both the number now a has value 50
b = a-b; // here we are extracting one number from the sum by sub
a = a-b; // the number so obtained in above help us to fetch the alternate number from sum
System.out.print("swapped numbers are a = "+ a+"b = "+ b);

Answer 2

BenAlabaster showed a practical way of doing a variable switch, but the try-catch clause is not needed. This code is enough.

static void Swap<T>(ref T x, ref T y)
{
     T t = y;
     y = x;
     x = t;
}

The usage is the same as he shown:

float startAngle = 159.9F
float stopAngle = 355.87F
Swap(ref startAngle, ref stopAngle);

You could also use an extension method:

static class SwapExtension
{
    public static T Swap<T>(this T x, ref T y)
    {
        T t = y;
        y = x;
        return t;
    }
}

Use it like this:

float startAngle = 159.9F;
float stopAngle = 355.87F;
startAngle = startAngle.Swap(ref stopAngle);

Both ways uses a temporary variable in the method, but you don't need the temporary variable where you do the swapping.

Answer 3

C# 7 introduced tuples which enables swapping two variables without a temporary one:

int a = 10;
int b = 2;
(a, b) = (b, a);

This assigns b to a and a to b.

Answer 4

Very simple code for swapping two variables:

static void Main(string[] args)
{
    Console.WriteLine("Prof.Owais ahmed");
    Console.WriteLine("Swapping two variables");

    Console.WriteLine("Enter your first number ");
    int x = Convert.ToInt32(Console.ReadLine());

    Console.WriteLine("Enter your first number ");
    int y = Convert.ToInt32(Console.ReadLine());

    Console.WriteLine("your vlaue of x is="+x+"\nyour value of y is="+y);

    int z = x;
    x = y;
    y = z;

    Console.WriteLine("after Swapping value of x is="+x+"/nyour value of y is="+y);
    Console.ReadLine();
}