CODEWITHSUNDEEP
javaoutputfactorial
user1858350
user1858350

Reputation: 115

Java factorial output

I am supposed to create a program that asks the user for a number and takes the factorial of that number then asks if they want to do another factorial (Y,N).

It is supposed to work like this:

My output is like:

After the change:

import java.util.Scanner;
public class factorial
{
    public static void main ( String [] args )
    {
      Scanner input = new Scanner(System.in);

        System.out.print("Enter a number you want to take the factorial of: ");
        int num = input.nextInt();

        int fact = 1;

        System.out.printf("%d! = %d\n ", num, Factorial(num, fact));

        System.out.print("Do another factorial (Y,N)? ");
        char  foo = input.next().charAt(0);

        while (foo != 'N')
        {
            System.out.print("Do another factorial (Y,N)? ");
            foo = input.next().charAt(0);

        System.out.print("Enter a number you want to take the factorial of: ");
        num = input.nextInt();

        System.out.printf("%d! = %d\n", num, Factorial(num, fact));
    }
}
    public static int Factorial(int num, int fact)
    {
        for (int i = 1; i <= num; i++)
            {   
                fact *= i;
            }
            return fact; 
    }

}

Output still has some problems:

Upvotes: 3

Views: 1612

Answers (5)

subodh
subodh

Reputation: 6158

This will help you.

public static void main ( String [] args )
     {
     String yesno ="Y";
     while(yesno.equalsIgnoreCase("y"))
     {
         Scanner input = new Scanner(System.in);
         System.out.print("Enter a number you want to take the factorial of: ");
         int num = input.nextInt();
         System.out.printf("%d! = %d\n ",num,fact(num));
         System.out.print("Do another factorial (Y,N)?");
         Scanner inputKey = new Scanner(System.in);
         yesno = inputKey.nextLine();

     }
     }

Here is factorial function:

public static int fact(int num)
    {
        if(num<=1)
        {
            return 1;

        }else{
            return (num*(fact(num-1))); 
        }
    }

Upvotes: 0

NPE
NPE

Reputation: 500893

You should refactor your code as follows:

  • There should be a method that takes an int and returns its factorial, and does nothing else.

  • All the input/output, as well as the "Do another factorial?" loop, should be done in main().

This will make it easier to get the logic right.

Upvotes: 0

Akshay Sahu
Akshay Sahu

Reputation: 79

Remove the below lines of code:

Scanner input = new Scanner(System.in); System.out.print("Do another factorial (Y,N)?");

from Factorial method.

Upvotes: 0

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 727047

You compute factorial, but you never print it:

System.out.printf("%d! = %d\n ", num, fact, Factorial(num, fact));

should be

System.out.printf("%d! = %d\n ", num, Factorial(num, fact));

Moreover, your Factorial function does not make use of the fact parameter, so you should remove it, and declare a local variable inside the function.

Finally, asking for the "do you want another factorial" should be done at the top level, not inside the Factorial function. Your code does not use the character that the user inputs, too: you'll need a loop that checks user's input, and continues while Y is entered.

Upvotes: 3

CloudyMarble
CloudyMarble

Reputation: 37576

Here is the error:

System.out.printf("%d! = %d\n ", num, fact, Factorial(num, fact))

Your output is not really Factorial(num, fact) but fact, this should be:

System.out.printf("%d! = %d\n ", num, Factorial(num, fact))

Upvotes: 1

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