FlowControl.cs

namespace BasicCoding;

internal static class FlowControl
{
    internal static void SimpleIf(int age)
    {
        if (age < 18)
        {
            Console.WriteLine("You are too young to buy alcohol in a bar in the UK.");
        }
    }

    [System.Diagnostics.CodeAnalysis.SuppressMessage(
        "Style",
        "IDE0011:Add braces",
        Justification = "This example deliberately shows the wrong way to do it")]
    internal static void BadIf(bool authenticationCodesCorrect)
    {
        if (authenticationCodesCorrect)
            SendTransferConfirmation();
            TransferFunds();
    }

    internal static void IfAndElse(bool optimistic)
    {
        if (optimistic)
        {
            Console.WriteLine("Glass half full");
        }
        else
        {
            Console.WriteLine("Glass half empty");
        }
    }

    internal static void MultipleElses(double temperatureInCelsius)
    {
        if (temperatureInCelsius < 52)
        {
            Console.WriteLine("Too cold");
        }
        else if (temperatureInCelsius > 58)
        {
            Console.WriteLine("Too hot");
        }
        else
        {
            Console.WriteLine("Just right");
        }
    }

    internal static void MultipleElsesLotsOfBlocks(double temperatureInCelsius)
    {
        if (temperatureInCelsius < 52)
        {
            Console.WriteLine("Too cold");
        }
        else
        {
            if (temperatureInCelsius > 58)
            {
                Console.WriteLine("Too hot");
            }
            else
            {
                Console.WriteLine("Just right");
            }
        }
    }

    internal static void SwitchWithStrings(string workStatus)
    {
        switch (workStatus)
        {
        case "ManagerInRoom":
            WorkDiligently();
            break;

        case "HaveNonUrgentDeadline":
        case "HaveImminentDeadline":
            CheckTwitter();
            CheckEmail();
            CheckTwitter();
            ContemplateGettingOnWithSomeWork();
            CheckTwitter();
            CheckTwitter();
            break;

        case "DeadlineOvershot":
            WorkFuriously();
            break;

        default:
            CheckTwitter();
            CheckEmail();
            break;
        }
    }

// To see the compiler error for Example 70, change this:
#if false
//  to:
// #if true
    internal static void IllegalSwitchFallThrough(string x)
    {
        switch (x)
        {
        case "One":
            Console.WriteLine("One");
        case "Two":  // This line will not compile
            Console.WriteLine("One or two");
            break;
        }
    }
#endif

    internal static void SwitchFallThrough(string x)
    {
        switch (x)
        {
        case "One":
            Console.WriteLine("One");
            goto case "Two";
        case "Two":
            Console.WriteLine("One or two");
            break;
        }
    }

    internal static void WhileLoop(StreamReader reader)
    {
        while (!reader.EndOfStream)
        {
            Console.WriteLine(reader.ReadLine());
        }
    }

    internal static void DoLoop()
    {
        char k;
        do
        {
            Console.WriteLine("Press x to exit");
            k = Console.ReadKey().KeyChar;
        }
        while (k != 'x');
    }

    internal static void ForLoops(int[] myArray)
    {
        for (int i = 0; i < myArray.Length; i++)
        {
            myArray[i] *= 2;
        }

        for (int i = 0, j = 0; i < myArray.Length; i++, j++)
        {
            myArray[i] = myArray[j] / 2;
        }
    }

    internal static void NestedLoop(int[,] myArray)
    {
        int height = myArray.GetLength(0);
        int width = myArray.GetLength(1);

        for (int j = 0; j < height; ++j)
        {
            for (int i = 0; i < width; ++i)
            {
                Console.WriteLine($"{i},{j}: {myArray[i, j]}");
            }
        }
    }

    internal static void ForeachLoops()
    {
        string[] messages = GetMessagesFromSomewhere();
        foreach (string message in messages)
        {
            Console.WriteLine(message);
        }

        static string[] GetMessagesFromSomewhere() => new[] { "Hello", "world" };
    }

    public static void ShowMessages(IEnumerable<string> messages)
    {
        foreach (string message in messages)
        {
            Console.WriteLine(message);
        }
    }

    private static void SendTransferConfirmation() => Console.WriteLine("Sending transfer confirmation");

    private static void TransferFunds() => Console.WriteLine("Transferring funds");

    private static void WorkDiligently() => Console.WriteLine("Makes Jack a dull boy");

    private static void CheckTwitter() => Console.WriteLine("Refresh");

    private static void CheckEmail() => Console.WriteLine("Scroll");

    private static void ContemplateGettingOnWithSomeWork() => Console.WriteLine("Sigh");

    private static void WorkFuriously() => Console.WriteLine("Here's Johnny!");
}