Question

I’m interested in both style and performance considerations. My choice is to do either of the following ( sorry for the poor formatting but the interface for this site is not WYSIWYG ):

One:

string value = "ALPHA";

switch ( value.ToUpper() )
{
   case "ALPHA":
     // do somthing
     break;
   case "BETA":
     // do something else
     break;
   default:
     break;
}

Two:

public enum GreekLetters
{
    UNKNOWN= 0,
    ALPHA= 1,
    BETA = 2,
    etc...

}

string value = "Alpha";
GreekLetters letter = (GreekLetters)Enum.Parse( typeof( GreekLetters ), value.ToUpper() );

switch( letter )
{
   case GreekLetters.ALPHA:
      // do something
      break;
   case GreekLetters.BETA:
      // do something else
      break;
   default:
      break;
}

Personally, I prefer option TWO below, but I don’t have any real reason other than basic style reasons. However, I’m not even sure there really is a style reason. Thanks for your input.

Answer 1

Option #1 is faster because if you look at the code for Enum.Parse, you’ll see that it goes through each item one by one, looking for a match. In addition, there is less code to maintain and keep consistent.

One word of caution is that you shouldn’t use ToUpper, but rather ToUpperInvariant() because of Turkey Test issues.

If you insist on Option #2, at least use the overload that allows you to specify to ignore case. This will be faster than converting to uppercase yourself. In addition, be advised that the Framework Design Guidelines encourage that all enum values be PascalCase instead of SCREAMING_CAPS.