## Program to find factorial of a number in C#

In this blog, we are going to learn How to find factorial of a positive number or integer in C#. As we know that we can find the factorial of a number in multiple ways, out of which I am going to share two ways i.e. with and without the use of recursion.

Program to find factorial of a number without using recursion:
In mathematics, factorial is the product of all positive numbers or integers less than or equal to the number.
 int number, factorial; Console.WriteLine("Enter a number to calculate its Factorial"); //Recieve input from user number = int.Parse(Console.ReadLine()); //set factorial value as we will start loop from number-1 factorial = number; //Multiply the factorial value till i becomes 1 for (int i=number-1;i>=1;i--) {     factorial = factorial * i; } //Display the output to the user Console.WriteLine("Factorial of " + number + " is: " + factorial); //Console.ReadLine() to hold the screen after the execution of the program Console.ReadLine();

Output:

Program to find the factorial of a number with the use of recursion:
A recursive function is a function that calls itself inside the function.
Program:
 class Program {     //CalculateFactorial method     public int CalculateFactorial(int number)     {         //If number becomes it will return 1 and recursion will stop         if (number == 1)         {             return 1;         }         else         {             //Calling CalculateFactorial method (Recursion)             return number * CalculateFactorial(number - 1);         }     }         static void Main(string[] args)     {         int number;         Console.WriteLine("Enter a number to calculate its Factorial");         //Recieve input from user         number = int.Parse(Console.ReadLine());         if (number > 0)         {             Program objProgram = new Program();             //Calling CalculateFactorial method             int factorial = objProgram.CalculateFactorial(number);             //Display the output to the user             Console.WriteLine("Factorial of " + number + " is: " + factorial);         }         else         {             Console.WriteLine("Number must be greater than zero");         }         //Console.ReadLine() to hold the screen after the execution of the program         Console.ReadLine();     } }

Output:

Thanks.