How to calculate factorial of a number in C++

[AZUL]

I am having problem coding in C++. I want to calculate the factorial of a number that the user inputs but the problem is that whatever logic I try to do, it fails. So I am here to know what are the possibilities and how do you calculate factorial of a user specified number in C++?

[Reegan]

You can calculate the factorial of a number in C++ using an external function as below and calling that function in your main code:

int calfactorial (int x)
{
 int finalx = 1;
 if (x==1) return 1;
 for (int i = 1; i <= x; ++i) finalx = finalx * i;
 return finalx;
}

[fellah]

Here is how factorial is calculated in C++:

# include <iostream.h>
int factorial (int);
int main()
{
    int result; 
    cout << "Enter your number: ";
    cin >> result;
    cout << "Factorial of " << result << "is "<< factorial (result) << endl;
}

int factorial (int n)
{
   int fact = 1;
   if  (n <= 1)
	 return 1;
   else
	 fact  = n * factorial (n - 1);
   return fact;
}