How to make a factorial program in C++

Question

I am new to this website; in fact this is my first question. So if I am asking this question in the wrong context, please inform me so I can make the adjustments. I have a program that is created in Visual Studio 2010 to allow a user to enter in an integer from 1 to 10. That user will click a button which in turn should compute and display the integer's factorial value in a text box. I thought everything looks correct but nothing is appearing in the text box.

The following code is what I have been using:

#pragma endregion
        private: System::Void btnFactorial_Click(System::Object^  sender, System::EventArgs^  e) 
        {
            int n;
            int nfact = 1;
            Int32::TryParse(txtNum->Text, n);
            if (n > 0)
            {
                for (int i = 1; i <= n; i++)
                    nfact *= i;
                txtResult->Text = nfact.ToString();
            }
            else
                MessageBox::Show ("Please enter a value > 0");      
        }

        private: int Factorial (int n)
        {
            if (n == 0)
                return 1;
            else
                return n * Factorial (n-1);
        }
    };
}

Can I ask for some help as to what I am doing wrong here?

Answer 1

You need to call your own function somewhere. Replace this:

for (int i = 1; i <= n; i++)
                nfact *= i;

and write this:

nfact = Factorial(n);