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# C++ Program to Find Factorial To Find Factorial of a positive integer n is equal factorial of a positive integer n is equal to 1*2*3*…n. You will learn to calculate the factorial of a number using for loop in this example.

To understand this example i.e C++ Program to Find Factorial, you should have the knowledge of following C++ programming topics:

• C++ for Loop

For any positive number n, it’s factorial is given by:

`factorial = 1*2*3...*n`

Factorial of a negative number cannot be found and factorial of 0 is 1.

In this program below, the user is asked to enter a positive integer. Then the factorial of that number is computed and displayed on the screen.

#### Find Factorial of a given number

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

int main()
{
unsigned int n;
unsigned long long factorial = 1;

cout << "Enter a positive integer: ";
cin >> n;

for(int i = 1; i <=n; ++i)
{
factorial *= i;
}

cout << "Factorial of " << n << " = " << factorial;
return 0;
}```

Output

```Enter a positive integer: 12
Factorial of 12 = 479001600```

Here variable factorial is of type `unsigned long long`.

It is because factorial of a number is always positive, that’s why `unsigned` the qualifier is added to it.

Since the factorial a number can be large, it is defined as `long long`.

#### Related Program

Ask your questions and clarify your doubts on how to find Factorial in C++ by commenting. Documentation.