c# - Enum and performance

Question

My app has a lot of different lookup values, these values don't ever change, e.g. US States. Rather than putting them into database tables, I'd like to use enums.

But, I do realize doing it this way involves having a few enums and a lot of casting from "int" and "string" to and from my enums.

Alternative, I see someone mentioned using a Dictionary<> as a lookup tables, but enum implementation seems to be cleaner.

So, I'd like to ask if keeping and passing around a lot of enums and casting them be a problem to performance or should I use the lookup tables approach, which performs better?

Edit: The casting is needed as ID to be stored in other database tables.

Answer 1

Casting from int to an enum is extremely cheap... it'll be faster than a dictionary lookup. Basically it's a no-op, just copying the bits into a location with a different notional type.

Parsing a string into an enum value will be somewhat slower.

I doubt that this is going to be a bottleneck for you however you do it though, to be honest... without knowing more about what you're doing, it's somewhat hard to recommendation beyond the normal "write the simplest, mode readable and maintainable code which will work, then check that it performs well enough."