CODEWITHSUNDEEP
c#factorial
user2008260
user2008260

Reputation: 1

Factorial for loop statement

I can't get this for loop to execute the factorial it is supposed to. It seems to only be looping once.

 static void Main(string[] args)
    {
    int a;
    int total=1;
    Console.WriteLine("Please enter any number");
    a = Convert.ToInt32 (Console.ReadLine());
    total = a;
        for (int intcount = a; intcount<= 1; intcount--)
          {
            total *= intcount;    
        }
        Console.WriteLine("Factorial of number '{0}' is '{1}'", a, total);
        Console.ReadKey();

Upvotes: 0

Views: 3697

Answers (5)

casillas
casillas

Reputation: 16813

Full solution is here! tested and works. Recursive Implementation as well as basic implementation

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication50
{
    class Program
    {
        static void Main(string[] args)
        {

        NumberManipulator manipulator = new NumberManipulator();
        Console.WriteLine("Please Enter Factorial Number:");
        int a= Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("---Basic Calling--");
        Console.WriteLine("Factorial of {0} is: {1}" ,a, manipulator.factorial(a));

        Console.WriteLine("--Recursively Calling--");
        Console.WriteLine("Factorial of {0} is: {1}", a, manipulator.recursively(a));

        Console.ReadLine();
    }
}

class NumberManipulator
{
    public int factorial(int num)
    {
        int result=1;
        int b = 1;
        do
        {
            result = result * b;
            Console.WriteLine(result);
            b++;
        } while (num >= b);
        return result;
    }

    public int recursively(int num)
    {
        if (num <= 1)
        {
            return 1;
        }
        else
        {
            return recursively(num - 1) * num;
        }
    }
  }
}

Upvotes: 0

Guffa
Guffa

Reputation: 700562

Loop while the value is larger than 1:

for (int intcount = a; intcount > 1; intcount--) {
  total *= intcount;
}

Alternatively, loop up to the value:

for (int intcount = 2; intcount <= a; intcount++) {
  total *= intcount;
}

Upvotes: 0

daryal
daryal

Reputation: 14929

total = 0;
for (int intcount = 1; intcount<= a; intcount++)
{
   total *= intcount;    
}

or 

total = a;
for (int intcount = a; intcount>= 1; intcount--)
  {
    total *= intcount;    
}

Upvotes: 0

Ilya Ivanov
Ilya Ivanov

Reputation: 23636

You should change initialization from total = a to total = 1 and intcount<= 1 to intcount > 1 like this:

var a = 5;
var total = 1;
for (int intcount = a; intcount > 1; intcount--)
{
     total *= intcount;    
}
Console.WriteLine (total);//prints 120

Upvotes: 0

SLaks
SLaks

Reputation: 887767

intcount<= 1

This is false as soon as you start your loop, so the loop exits immediately.

You probably want to loop while that number is more than 1.

Upvotes: 5

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