Use an enum or abstract base class in a game in Objective-C

Context: In a game, when each level is completed, a Rating is stored based on player performance: Poor, Good, Excellent. The ratings are later used to evaluate the game play as a whole.

Question: Should the Rating object contain a rating choice as an enum {RatingPoor, RatingGood, RatingExcellent} or should I make an abstract base class Rating with subclasses RatingPoor, RatingGood, RatingExcellent.

Other details

Ratings don't have complex behaviors, they are just generated from play stats at a very low frequency like every minute. They're assigned to a collection and averaged at the e开发者_StackOverflow社区nd of a game to generate a Rank (like Cadet, Pilot, Captain, Admiral). At the end of a level, the rating is shown as an icon (think stars, like in Angry Birds). They also get stored when the player pauses or suspends the game.

I would also appreciate knowing how to decide on enum vs. subclass, given this context.

This situation is basic enough that you should just use an enum. I typically use enum's when something can be represented by an integer (a mode, a setting, or in your case, a rating,). A subclass is only necessary if your ratings would include additional attributes or relationships.

I think that a subclass would be overkill for this situation, as it doesn't sound like you're attaching any particular methods to each rating. I would use an enum.

I'm no expert in software design, but I generally err towards using the simplest data structures that will get a job done-- in general, if the problem doesn't require you to have methods travelling with the data, a class would be more heavyweight than necessary.