method not returning correct value

Question

I have a method to check if the user wants to play another game, the problem is that if the user enters an invalid input then after a correct input anotherGame is still set to Y

When it exits the method the value of anotherGame is still Y even if they select N if they enter an incorrect input

When this block of code runs anotherGame is returning Y no matter what.

else
{
     Console.WriteLine("ERROR: Invalid input (Y/N) only!");
     promptRedo(anotherGame);
}

CODE EXAMPLE:

using System;

public class Program
{
    public static void Main()
    {
        string anotherGame = "y";
        while (anotherGame == "y")
        {
            anotherGame = promptRedo(anotherGame);
            Console.WriteLine(anotherGame);
        }
    }
    static String promptRedo(String anotherGame)
    {
        Console.Write("Would you like to play another game? (Y/N) => ");
        String input = Console.ReadLine().ToLower();
        if (input.Equals("y"))
        {
            anotherGame = "y";
        }
        else if (input.Equals("n"))
        {
            // get any key from user to exit program
            Console.WriteLine();
            Console.WriteLine("Thank you for playing!");
            Console.WriteLine("Press any key to exit ...");
            Console.ReadKey();
            anotherGame = "n";
            Console.WriteLine(anotherGame);
        }
        else
        {
            Console.WriteLine("ERROR: Invalid input (Y/N) only!");
            promptRedo(anotherGame);
        }
        return anotherGame;
    }
}

Answer 1

You don't need the recursive call, all you need to do is to remove

promptRedo(anotherGame);

From the else section inside promptRedo function.

Answer 2

This function does not need an argument to be passed. instead of calling function again and againg just put it in a loop:

static String promptRedo()
{ 
    String anotherGame = ""
    do
    {
        Console.Write("Would you like to play another game? (Y/N) => ");
        String input = Console.ReadLine().ToLower();
        if (input.Equals("y"))
        {
            anotherGame = "y";
        }
        else if (input.Equals("n"))
        {
            // get any key from user to exit program
            Console.WriteLine();
            Console.WriteLine("Thank you for playing!");
            Console.WriteLine("Press any key to exit ...");
            Console.ReadKey();
            anotherGame = "n";
            Console.WriteLine(anotherGame);
        }
        else
        {
            Console.WriteLine("ERROR: Invalid input (Y/N) only!");
        }
    } while(anotherGame != "y" && anotherGame != "n")
    return anotherGame;
}

Answer 3

else
{
     Console.WriteLine("ERROR: Invalid input (Y/N) only!");
     promptRedo(anotherGame);
}

In this code you are just calling promptRedo() and returning anotherGame at the end of function. But you are supposed to return from promptRedo().

Your code must be like below

else
{
     Console.WriteLine("ERROR: Invalid input (Y/N) only!");
     return promptRedo(anotherGame);
}

Answer 4

you haven't assigned the of "promptRedo(anotherGame)" method to "anotherGame" variable in else block.

Instead of:

    else
    {
        Console.WriteLine("ERROR: Invalid input (Y/N) only!");
        promptRedo(anotherGame);
    }

you should write:

     else
    {
        Console.WriteLine("ERROR: Invalid input (Y/N) only!");
        anotherGame = promptRedo(anotherGame);
    }