best way to store / lookup name value pairs

Question

I have a list of error codes I need to reference, kinda like this:

Code / Error Message  
A01 = whatever error  
U01 = another error  
U02 = yet another error type

I get the Code returned to me via a web service call and I need to display or get the readable error. So I need a function when passed a Code that returns the readable description. I was just going to do a select case but thought their might be a better way. What is the best way / most effieient way to do this?

Answer 1

Statically initialized Hashmap?

Answer 2

Use a Dictionary, (in C#, but the concept and classes are the same):

// Initialize this once, and store it in the ASP.NET Cache.
Dictionary<String,String> errorCodes = new Dictionary<String,String>();

errorCodes.Add("A01", "Whatever Error");
errorCodes.Add("U01", "Another Error");


// And to get your error code:

string ErrCode = errorCodes[ErrorCodeFromWS];

Answer 3

You would use a dictionary. A dictionary uses a hashmap internally for performance, so it is good in that regard. Also, because you want this to go as quickly as possible by the sounds of it, I would statically initialize it in its own class instead of, for example, in an XML file or slimier. You would probably want something like:

public static class ErrorCodes
{
    private static Dictonary<string, string> s_codes = new Dicontary<string, string>();
    static ErrorCodes()
    {
         s_codes["code"] = "Description";
         s_codes["code2"] = "Description2";
    }

    public static string GetDesc(string code)
    {
         return s_codes[code];
    }
}

That way, if you wanted to move the back end to a file instead of being static, then you could.