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Write a program that takes a decimal value between 1 and 10 and dis- plays its equivalent Roman numeral value. Display an error message if the value entered is outside of the acceptable range. Write a two class solution. The second class should allow the user to input a test value.

What I have tried:

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

namespace Pg322number1
    class Program
        static void Main(string[] args)
            int value;
            string roman;

            value = GetDecimal();

            roman = CalculateRoman(value);

            DisplayResults(value, roman);

        public static void DisplayInstrution()
            Console.WriteLine("This application allows decimal value between 1 and 10");
            Console.WriteLine("to be entered. It displays the equivalent roman numeral value.");

        public static int GetDecimal()
            int value;
            Console.WriteLine("Decimal value: ");
            value = Int32.Parse(Console.ReadLine());

            return value;

        public static string CalculateRoman(int value)
            string result;

            if (value < 0 || value > 10)
                result = "Invalid input";
                if (value == 1)
                result = "I";
                if (value == 2)
                result = "II";
                if (value == 3)
                result = "III";
                if (value == 4)
                result = "IV";
                if (value == 5)
                result = "V";
                if (value == 6)
                result = "VI";
                if (value == 7)
                result = "VII";
                if (value == 8)
                result = "VIII";
                if (value == 9)
                result = "IX";
                result = "IX";

            return result;


        public static void DisplayResults(int value, string roman)
            if (value != 0)
                Console.WriteLine("Roman value: " + roman);
Updated 2-Jul-20 20:55pm
PIEBALDconsult 2-Jul-20 22:27pm
Ummm, well, what compiler error do you get?
Dave Kreskowiak 2-Jul-20 22:34pm
No idea. That code compiles cleanly so I have no idea what you're talking about as far as compiler errors.
Patrice T 2-Jul-20 22:39pm
What is error message from compiler ?
Richard MacCutchan 3-Jul-20 3:57am
Every question you have posted seems to use this hardcoded way of generating value conversions like you have above. That is not the way to do conversions from one numbering system to another. You need to calculate the values using divisions and remainders, string tables etc.

Compiling and running are different processes - your code as shown compiles without problems, as others have said. But ...

Compiling does not mean your code is right! :laugh:
Think of the development process as writing an email: compiling successfully means that you wrote the email in the right language - English, rather than German for example - not that the email contained the message you wanted to send.

So now you enter the second stage of development (in reality it's the fourth or fifth, but you'll come to the earlier stages later): Testing and Debugging.

Start by looking at what it does do, and how that differs from what you wanted. This is important, because it give you information as to why it's doing it. For example, if a program is intended to let the user enter a number and it doubles it and prints the answer, then if the input / output was like this:
Input   Expected output    Actual output
  1            2                 1
  2            4                 4
  3            6                 9
  4            8                16
Then it's fairly obvious that the problem is with the bit which doubles it - it's not adding itself to itself, or multiplying it by 2, it's multiplying it by itself and returning the square of the input.
So with that, you can look at the code and it's obvious that it's somewhere here:
private int Double(int value)
   return value * value;

Once you have an idea what might be going wrong, start using the debugger to find out why. Put a breakpoint on the first line of the method, and run your app. When it reaches the breakpoint, the debugger will stop, and hand control over to you. You can now run your code line-by-line (called "single stepping") and look at (or even change) variable contents as necessary (heck, you can even change the code and try again if you need to).
Think about what each line in the code should do before you execute it, and compare that to what it actually did when you use the "Step over" button to execute each line in turn. Did it do what you expect? If so, move on to the next line.
If not, why not? How does it differ?
Hopefully, that should help you locate which part of that code has a problem, and what the problem is.
This is a skill, and it's one which is well worth developing as it helps you in the real world as well as in development. And like all skills, it only improves by use!
Sorry, I can't help you. Your program compiles and runs well.

It is slightly off when one enters 10...

t778987 2-Jul-20 23:44pm
how do I fix where it is slightly off? Also should I add classes?
Luc Pattyn 3-Jul-20 0:03am
Did you run your code? with different inputs?
did you carefully read the assignment? did you fulfill all requirements?

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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