an example for a blog post - comments on what, revisited

whatcomments2.cs

public static void Main(string[] args)
{
    var accountId = "1234";

    ValidateUser(accountId);

    var action = GetTransactionType(accountId);
    var amount = GetTransactionAmount(accountId);

    ShowTransactionAndBalance(accountId, action, amount);
}

private static void ShowTransactionAndBalance(string accountId, string action, decimal amount)
{
    var name = GetUserName(accountId);
    var balance = GetBalance(accountId);

    Console.WriteLine($"\nThanks {name}, we recorded your {(action == "D" ? "deposit" : "withdrawal")} of ${amount}.");

    Console.WriteLine($"For your records, you now have ${(balance + (action == "D" ? amount : -amount))} in your account.");
}

private static bool ValidateUser(string accountId)
{
    var secretAnswer = GetSecret(accountId);

    GetUserInput("Provide your secret answer before continuing:",
                 (answer) => answer == secretAnswer,
                 "WRONG!!!");

    return true;
}

private static string GetTransactionType(string accountId)
{
    var name = GetUserName(accountId);

    return GetUserInput($"Hello {name}, [W]ithdrawal or [D]eposit?",
                        (tranType) => tranType == "D" || tranType == "W",
                        "Invalid option!");
}

private static decimal GetTransactionAmount(string accountId)
{
    var balance = GetBalance(accountId);

    var amount = GetUserInput($"How much is this transaction for? (You have ${balance})",
                              (amt) => Decimal.TryParse(amt, out decimal a) && Decimal.Parse(amt) > 0,
                              "Invalid amount!");

    return Decimal.Parse(amount);
}

private static string GetSecret(string accountId)
{
    return "42";
}

private static string GetUserName(string accountId)
{
    return "Grant";
}

private static decimal GetBalance(string accountId)
{
    return 100m;
}

private static string GetUserInput(string prompt, Func<string, bool> isValidAnswer, string errorMessage)
{
    var answer = "";

    while (!isValidAnswer(answer))
    {
        Console.Write(prompt + " ");
        answer = Console.ReadLine();

        if (!isValidAnswer(answer))
            Console.WriteLine($"\n{errorMessage}");
    }

    return answer;
}