Problem with random number in C#

Question

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

namespace _1DV402.S2.L04
{
class SecretNumber
{
    // Fields
    private int _count;
    private int _secretNumber;
    public const int MaxNumberOfGuesses = 7;

    public SecretNumber()
    {
        //_count = 0;
        //_secretNumber = 0;
        Initialize();
    }

    public void Initialize()
    {
        // Randomize a number between 1-100.
        Random random = new Random();
        int _secretNumber = random.Next(1, 101);

        Console.WriteLine(_secretNumber);
    }

    public bool MakeGuess(int number)
    {
        if(number > _secretNumber)
        {
            _count++;
            Console.WriteLine("{0} is too high. You have {1} guesses left", number,    MaxNumberOfGuesses - _count);

            return false;
        }
        else if (number < _secretNumber)
        {
            Console.WriteLine("{0} is too low. You have {1} guesses left", number, _count);
            return false;
        }
        else
        {
            Console.WriteLine("Congratulations. You did it {0}.", _count);
            return true;
        }
    }
}

}

And my Main:

using System;

namespace _1DV402.S2.L04
{
class Program
{
    static void Main(string[] args)
    {
        int number = 0;
        SecretNumber secretNumber = new SecretNumber();

        Console.WriteLine(new String('*', 40));
        Console.Write("Gissar på 0 ");
        Console.ForegroundColor = ConsoleColor.White;
        Console.BackgroundColor = ConsoleColor.Red;
        Console.WriteLine("(ska inte bli rätt!)");
        Console.ResetColor();
        secretNumber.MakeGuess(0);
        Console.WriteLine(new String('*', 40));

        do
        {
            secretNumber.Initialize();
            Console.WriteLine("\nGissa ett tal mellan 1-100");
            for (int i = 1; i <= SecretNumber.MaxNumberOfGuesses; i++)
            {
                do
                {
                    Console.Write("Gissning {0}: ", i);
                } while (!int.TryParse(Console.ReadLine(), out number));

                if (secretNumber.MakeGuess(number))
                {
                    break;
                }
            }
            Console.Write("Nytt hemligt nummer? [N] avbryter.");
        } while (Console.ReadKey(true).Key != ConsoleKey.N);
    }
}

}

My problem is _secretNumber is allways 0 when i try to check it in my if-statements in MakeGuess.

how can i solve the problem so the program works?

Answer 1

i wonder how could this possibly compile... you declare your _secret number within the scope of your Initialize() method, so the variable goes out of scope as soon as you're finished with initialization.

You should declare the _secret number as a private field, within the scope of your class.

Cheers!

Answer 2

You're re-declaring a second _secretNumber variable here, which hides the _secretNumber field:

public void Initialize()
{
    // Randomize a number between 1-100.
    Random random = new Random();

    int _secretNumber = random.Next(1, 101);
    // ^^^
    // Should be:
    // _secretNumber = random.Next(1, 101);

    Console.WriteLine(_secretNumber);
}

Answer 3

In Initialize you are declaring it as a method variable. This only exists inside the method, and takes precedence over the field (aka this._secretNumber).

Rather than

// declares and assigns a method variable
int _secretNumber = ...

Just use

// assigns the field
_secretNumber = ...