Question

I was wondering about C# Enumerations and what happens with duplicate values. I created the following small program to test things out:

namespace ConsoleTest
{

    enum TestEnum
    {
        FirstElement = -1,
        SecondElement,
        ThirdElement,
        Duplicate = FirstElement
    }

    /// <summary>
    /// Summary description for MainConsole.
    /// </summary>
    public class MainConsole
    {
        /// <summary>
        /// Constructor for the class.
        /// </summary>
        public MainConsole()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        /// <summary>
        /// Entry point for the application.
        /// </summary>
        /// <param name="args">Arguments to the application</param>
        public static void Main(string[] args)
        {
            TestEnum first = TestEnum.FirstElement;
            TestEnum second = TestEnum.SecondElement;
            TestEnum duplicate = TestEnum.Duplicate;

            foreach (string str in Enum.GetNames(typeof(TestEnum)))
            {
                Console.WriteLine("Name is: " + str);
            }

            Console.WriteLine("first string is: " + first.ToString());
            Console.WriteLine("value is: " + ((int)first).ToString());
            Console.WriteLine("second string is: " + second.ToString());
            Console.WriteLine("value is: " + ((int)second).ToString());
            Console.WriteLine("duplicate string is: " + duplicate.ToString());
            Console.WriteLine("value is: " + ((int)duplicate).ToString());

            TestEnum fromStr = (TestEnum)Enum.Parse(typeof(TestEnum), "duplicate", true);
            Console.WriteLine("fromstr string is: " + fromStr.ToString());
            Console.WriteLine("value is: " + ((int)fromStr).ToString());
            if (fromStr == TestEnum.Duplicate)
            {
                Console.WriteLine("Duplicate compares the same as FirstElement");
            }
            else
            {
                Console.WriteLine("Duplicate does NOT compare the same as FirstElement");
            }

        }
    }
}

Which produces the following output:

Name is: SecondElement
Name is: ThirdElement 
Name is: FirstElement
Name is: Duplicate
first string is: FirstElement
value is: -1
second string is: SecondElement
value is: 0
duplicate string is: FirstElement
value is: -1
fromstr string is: FirstElement
value is: -1
Duplicate compares the same as FirstElement
Press any key to continue . . .

This seems to be EXACTLY what I want and expect since I’m constructing something that a version tag will increment every so often, so I want something that I can “assign” to the current version, and even compare to it.

Here’s the question though: what’s the pitfalls of this approach? Is there one? Is it just bad style (I don’t want to end up on thedailywtf)? Is there a lot better way of doing something like this? I’m on .NET 2.0 and do NOT have the option to go to 3.5 or 4.0.

Opinions are welcome.

Answer 1

Its not clear what you’re trying to achieve, but it doesn’t look great to me. Adding another entry to the enum after ‘Duplicate’ for example will take the value 0 unless you explicitly set the value again.