Program for 3 Different ways to calculate factorial in C#

Factorial of a number is obtained from the result of multiplying a series of descending natural numbers.

This C# Program generates Factorial of the Number obtained from the user.

1. Using For Loop:

/*
* C# Program to Generate the Factorial of Given Number
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace factorial
{
class Program
{
static void Main(string[] args)
{
int i, number, fact;
Console.WriteLine("Enter the Number");
number = int.Parse(Console.ReadLine());
fact = number;
for (i = number - 1; i >= 1; i--)
{
fact = fact * i;
}
Console.WriteLine("\nFactorial of Given Number is: "+fact);
Console.ReadLine();

}
}
}

Here is the output of the C# Program:

Enter the Number
5
Factorial of Given Number is: 120

You can calculate factorial using recursion and while loop also.

2. Using Recursion:

public double factorial_Recursion(int number)
{
if (number == 1)
return 1;
else
return number * factorial_recursion(number - 1);
}

3. Using While loop:

public double factorial_WhileLoop(int number)
{
double result = 1;
while (number != 1)
{
result = result * number;
number = number - 1;
}
return result;
}

Source: csharpstar

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