# C# Program to swap two numbers using temporary variable and without using third variable

How to write a C# Program to swap two numbers, how to swap two numbers with temporary variable,how to swap two numbers without using third variable.

# What is Swapping of Numbers ?

The act of swapping two variables refers to mutually exchanging the values of the variables. Generally, this is done with the data in memory.

## Swap Two Numbers with Third Variable

The simplest method to swap two variables is to use a third temporary variable .

### Algorithm of swapping two numbers with temporary variable:

Step 1: Define 3 variables x, y and temp;

Step 2: give values to the x and y;

Step 3: temp = x ;

Step 4: x = y ;

Step 5: y = temp;

Step 6: Print values of x and y;

### Program of swapping two numbers with temporary variable in C#

```using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Program
{
class Program
{
static void Main(string[] args)
{
int num1, num2, temp;
Console.Write("\n Enter the First Number : ");
num1 = int.Parse(Console.ReadLine());
Console.Write("\n Enter the Second Number : ");
num2 = int.Parse(Console.ReadLine());
temp = num1;
num1 = num2;
num2 = temp;
Console.Write("\n After Swapping : ");
Console.Write("\n First Number : "+num1);
Console.Write("\n Second Number : "+num2);
Console.Read();
}
}
}```

#### Input & output:

```Enter the First Number : 5
Enter the Second Number : 7
After Swapping :
First Number : 7
Second Number : 5```

## How to swap two numbers without using a temporary variable

If given two variables are x, and y, swap two variables without using a third variable.There is a common way to swap two numbers without using third variable.

Using Arithmetic Operators : The idea is to get a sum in one of the two given numbers. The numbers can then be swapped using the sum and subtraction from the sum.

### C# Program to Swap Two Numbers without third variable

```using System;

namespace CSharpProgram
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("\n Enter first number");
int n1 = int.Parse(Console.ReadLine());
Console.WriteLine("\n Enter second number");
int n2 = int.Parse(Console.ReadLine());
Console.WriteLine("\n Numbers Before swap n1 = " + n1 + " n2 = " + n2);
n1 = n1 * n2; //n1=50 (5*10)
n2 = n1 / n2; //n2=5 (50/10)
n1 = n1 / n2; //n1=10 (50/5)
Console.Write("\n After swap n1 = " + n1 + " n2 = " + n2);
Console.ReadLine();
}

}
}
```

#### Input & Output:

```Enter first number 27
Enter second number 15
Numbers Before swap n1 = 27 n2 = 15
After swap n1 = 15 n2 = 27```

So in this post we have learn how to swap two numbers using temporary variable or without using temporary variable.