3.9. Enumerations

Remember our examples involving various breeds of dog? In thinking about the types in these programs, we might want a top-level Breed type that keeps track of a number of breeds. Such a type is called an enumerated type, and the values it contains are called enumerations.

While enumerations are a built-in part of many programming languages, Scala takes a different route and implements them as a class in its standard library. This means there is no special syntax for enumerations in Scala, as in Java and C#. Instead, you just define an object that extends the Enumeration class. Hence, at the byte code level, there is no connection between Scala enumerations and the enum constructs in Java and C#.