# Factorial Using Function Example Program In C++

## Definition

In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example,

``6! = 6 x 5 x 4 x 3 x 2 x 1 = 720``

The value of 0! is 1, according to the convention for an empty product.

## Factorial Using Function Example Program

``````/*  Example Program For Factorial Value Using Function In C++
little drops @ thiyagaraaj.com

Coded By:THIYAGARAAJ MP             */

#include<iostream>
#include<conio.h>

using namespace std;

//Function
long factorial(int);

int main() {

// Variable Declaration
int counter, n;

// Get Input Value
cout << "Enter the Number :";
cin>>n;

// Factorial Function Call
cout << n << " Factorial Value Is " << factorial(n);

// Wait For Output Screen
getch();
return 0;
}

// Factorial Function

long factorial(int n) {
int counter;
long fact = 1;

//for Loop Block
for (int counter = 1; counter <= n; counter++) {
fact = fact * counter;
}

return fact;
}``````

## Sample Output

``````Enter the Number :6
6 Factorial Value Is 720``````