Loop troubles in C#

Question

I seem to having a problem where I need an integer from a loop for the loop condition, here's the code:

do {
    Console.WriteLine();
    Console.WriteLine("What file would you like to test?");
    Console.WriteLine("1. Royal Flush");
    Console.WriteLine("2. Straight Flush");
    Console.WriteLine("3. Four of a Kind");
    Console.WriteLine("4. Full House");
    Console.WriteLine("5. Flush");
    Console.WriteLine("6. Straight");
    Console.WriteLine("7. Three of a Kind");
    Console.WriteLine("8. Two Pair");
    Console.WriteLine("9. Pair");
    Console.WriteLine("10. Exit");
    choiceInt = Convert.ToInt32(Console.ReadLine());
} while (choiceInt < 10 || choiceInt > 0);

I need the choiceInt for the condition of the loop, to get this to work at the moment i have to let it loop through once before it gets a value,

Answer 1

You have your > and < wrong: you want a condition that evaluates to true when the choice is wrong (hence the loop should continue asking the user for input). Since do / while exits when the condition turns false , you can be sure that after exiting the loop choiceInt is in the valid range.

The condition should look like this:

do {
    ...
} (choiceInt < 0 || choiceInt > 10);
//    ^^^^              ^^^^
//  negative          above ten

Answer 2

This will work for you:

    static void Main(string[] args)
    {
        string consoleInput;
        ShowOptions();         

        do
        {
            consoleInput = Console.ReadLine();
            if (consoleInput == "10")
                Environment.Exit(0);

            DoSomething();
            ShowOptions();

        } while (consoleInput != null && consoleInput != "10");
    }

    private static void ShowOptions()
    {
        Console.WriteLine();
        Console.WriteLine("What file would you like to test?");
        Console.WriteLine("1. Royal Flush");
        Console.WriteLine("2. Straight Flush");
        Console.WriteLine("3. Four of a Kind");
        Console.WriteLine("4. Full House");
        Console.WriteLine("5. Flush");
        Console.WriteLine("6. Straight");
        Console.WriteLine("7. Three of a Kind");
        Console.WriteLine("8. Two Pair");
        Console.WriteLine("9. Pair");
        Console.WriteLine("10. Exit");
    }

    private static void DoSomething() { Console.WriteLine("I am doing something!"); }

Answer 3

I would be inclined to try an tidy up the code to make it more generic. Try doing this:

var options = new []
{
    new { option = 1, text = "Royal Flush" },
    new { option = 2, text = "Straight Flush" },
    new { option = 3, text = "Four of a Kind" },
    new { option = 4, text = "Full House" },
    new { option = 5, text = "Flush" },
    new { option = 6, text = "Straight" },
    new { option = 7, text = "Three of a Kind" },
    new { option = 8, text = "Two Pair" },
    new { option = 9, text = "Pair" },
    new { option = 10, text = "Exit" },
};

string choice;
do
{
    Console.WriteLine();
    Console.WriteLine("What file would you like to test?");
    Console.WriteLine(
        String.Join(
            Environment.NewLine,
            options.Select(o => String.Format("{0}. {1}", o.option, o.text))));
    choice = Console.ReadLine();
} while (options.Take(9).Any(o => o.option.ToString() == choice));