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Arrays and Enumerated Types
Enumerated Types
An
enum is a language construct that is used to define type-safe
enumerations which can be used when a fixed set of named values is desired.
All enums implicitly extend
java.lang.Enum. Enums may contain one or more
enum constants, which define unique
instances of the enum type. An enum declaration defines an
enum type
which is very similar to a class in that it may have members such as fields,
methods, and constructors (with some restrictions).
Since enums are classes, reflection has no need to define an explicit
java.lang.reflect.Enum class. The only Reflection APIs that are
specific to enums are
Class.isEnum(),
Class.getEnumConstants(), and
java.lang.reflect.Field.isEnumConstant(). Most reflective operations involving enums are the same as any other class
or member. For example, enum constants are implemented as public static
final fields on the enum. The following sections show how to use
Class
and
java.lang.reflect.Field
with enums.
For an introduction to enums, see the
lesson.
