how to create an EnumMap object with key and value both as Enum?

Question

enum Month{JANUARY, FEBRUARY, MARCH, ...
}

enum Week{MONDAY, TUESDAY, WEDNESDAY, ...
}

Map<Month, String> monthMap = new EnumMap<>(Month.class); Simple EnumMap can be created like this where key is Enum and value is String

However, I want to create the EnumMap where key and value both are of enum type.

Map<Month, Week> monthWeekMap = new EnumMap<> ....
what will be the syntax for creating the above enum map objet.

Basil Bourque · Accepted Answer · 2021-02-24 19:22:04Z

5

The syntax is no different:

Map<Month, Week> monthWeekMap = new EnumMap<>(Month.class);

The EnumMap constructor only needs the Class of the key type, in order to decide how to allocate the array used for the actual storage (an EnumMap is effectively just a strongly-typed array, whose length is the number of elements in the enum: this is obtained by reflection); the value type is essentially irrelevant, because it's just storing Object values internally.

edited Feb 24, 2021 at 19:22

Basil Bourque

347k130 gold badges950 silver badges1.3k bronze badges

answered Feb 24, 2021 at 15:36

Andy Turner

141k11 gold badges169 silver badges263 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

how to create an EnumMap object with key and value both as Enum?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related