Convert Enum to String

Question

Which is the preferred way to convert an Enum to a String in .NET 3.5?

• Enum.GetName
• Enum.Format
• toString

Why should I prefer one of these over the others? Does one perform better?

Justification for Accepted Answer

Based on the forum post in panesofglass answer, it appears that Microsoft indirectly endorses the following method of converting an enum value to a string.

Do not convert an enum value to a string using built-in enum methods.

...

This will cause problems when Dotfuscating. You should not use enum.ToString(), enum.GetNames(), enum.GetName(), enum.Format() or enum.Parse() to convert an enum to a string. Instead, use a switch statement, and also internationalize the names if necessary.

Answer 1

Enum.GetName()

Format() is really just a wrapper around GetName() with some formatting functionality (or InternalGetValueAsString() to be exact). ToString() is pretty much the same as Format(). I think GetName() is best option since it's totally obvious what it does for anyone who reads the source.

Answer 2

I don't know what the "preferred" method is (ask 100 people and get 100 different opinions) but do what's simplest and what works. GetName works but requires a lot more keystrokes. ToString() seems to do the job very well.

Answer 3

Best I can find is this question on MSDN, which asks a different question, but the rule XML describe the reason as breaking Dotfuscation. Any other concerns appear to relate to indirect boxing (GetName and Format). Unfortunately, I can't find any performance reasons for using any of the above.

Answer 4

All of these internally end up calling a method called "InternalGetValueAsString". The difference between ToString and GetName would be that GetName has to verify a few things first:

1. The type you entered isn't null.
2. The type you entered is, in fact an enumeration.
3. The value you passed in isn't null.
4. The value you passed in is of a type that an enumeration can actually use as it's underlying type, or of the type of the enumeration itself. It uses GetType on the value to check this.

.ToString doesn't have to worry about any of these above issues, because it is called on an instance of the class itself, and not on a passed in version, therefore, due to the fact that the .ToString method doesn't have the same verification issues as the static methods, I would conclude that .ToString is the fastest way to get the value as a string.

-David Morton

Answer 5

I create a "Description" extension method and attach it to the enum so that i can get truly user-friendly naming that includes spaces and casing. I have never liked using the enum value itself as displayable text because it is something we developers use to create more readable code. It is not intended for UI display purposes. I want to be able to change the UI without going through and changing enums all over.