C++ Program to Find Factorial of Number (2 Ways)

In this program, we will learn how to write to Find Factorial of a Number using the C++ programming language.

What is Factorial of a Number?

Factorial of a non-negative integer n is the product of all the positive integers that are less than or equal to n.For example: The factorial of 5 is 120.
5! = 5 * 4 * 3 * 2 *1
5! = 120

We will discuss two ways to write code for it.

  1. Using loop
  2. Using recursion

Let's discuss these ways one by one

C++ Programming Code to Find Factorial of Number

Using loop

We will use the for loop in this program. The loop will execute until the number provided by the user is reached.

And in the body of the loop fact variable will be multiplied with the current value i.e. value of i variable and store it back to fact variable.

Code:-

#include <iostream>

using namespace std;

int main() {
   int num, fact = 1;

   cout << "Enter a number: ";
   cin >> num;

   for(int i=1; i<=num; i++){
       fact = fact * i;
   }  

   cout<<"Factorial of " << num << " is " << fact << endl;

   return 0;
}

Output:-

Enter a number: 5
Factorial of 5 is 120

Using recursion

Recursion will be used in this program.

If the base condition is found it will return 1 else it will return the product of n and the factorial of n-1.

code:-

#include <iostream>

using namespace std;

int fact(int n) { 
   if ((n==0)||(n==1))
      return 1;
   else
      return n*fact(n-1);
}

int main() {
   int num;

   cout << "Enter a number: ";
   cin >> num;

   cout<<"Factorial of " << num << " is " << fact(num) << endl;
   
   return 0;
}

Output:-

Enter a number: 5
Factorial of 5 is 120

You can learn about many other C++ Programs Here.







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Amit Rawat

Amit Rawat

Founder and Developer at SpiderLabWeb
I love to work on new projects and also work on my ideas. My main field of interest is Web Development.

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