# C++ Program to swap two numbers with and without third variable

This article guide you for writing a Program in C++ which swap the two numbers. Here, We had discussed two methods to swap the two numbers in C++ :

1. Using Third Variable
2. Without Using Third Variable

## Using Third Variable

Let’s see a simple C++ example to swap two numbers using third variable.

```#include <iostream>
using namespace std;

int main()
{
int a = 4, b = 6, temp;

cout << "Before swapping." << endl;
cout << "a = " << a << ", b = " << b << endl;

temp = a;
a = b;
b = temp;

cout << "\nAfter swapping." << endl;
cout << "a = " << a << ", b = " << b << endl;

return 0;
}```

Output:

```Before swapping.
a = 4, b = 6

After swapping.
a = 6, b = 4```

## Without Using Third Variable

We can swap two numbers without using third variable. There are two common ways to swap two numbers without using third variable:

1. By product and divide

### Program 1: Using product and divide

Let’s see a simple C++ example to swap two numbers without using third variable.

```     #include <iostream>
using namespace std;
int main()
{
int a=4, b=6;
cout<<"Before swap a= "<<a<<", b= "<<b<<endl;
a=a*b; //a=24 (4*24)
b=a/b; //b=4 (24/6)
a=a/b; //a=6 (24/4)
cout<<"After swap a= "<<a<<", b= "<<b<<endl;
return 0;
}  ```

Output:

```Before swap a= 4, b= 6
After swap a= 6, b= 4```

### Program 2: Using addition and subtraction

Let’s see another example to swap two numbers using addition( + ) and subtraction( – ).

```    #include <iostream>
using namespace std;
int main()
{
int a=4, b=6;
cout<<"Before swap a= "<<a<<", b= "<<b<<endl;
a=a+b; //a=10 (4+6)
b=a-b; //b=4 (10-6)
a=a-b; //a=6 (10-4)
cout<<"After swap a= "<<a<<", b= "<<b<<endl;
return 0;
}  ```

Output:

`Before swap a= 4, b= 6After swap a= 6, b= 4`
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## Conclusion:

Hi guys, I can hope that you can know that how to write a Program in C++ which swap the two numbers. If you like this post as well as know something new so share this article in your social media accounts. If you have any doubt related to this post then you ask in comment section.

Categories C++