Determine the enum value using a value

Question

I am stuck on what feels like a seemingly simple question.

Say I have the following enum:

   enum CARDS {

        JOKER(1),
        JACK(2),
        QUEEN(3),
        KING(4),
        ACE(5)
        ;

        private final int cardNumber;

        CARDS(int cardNumber) {

            this.cardNumber = cardNumber;

        }

    }

I would like to find a way to determine the value of an enum (JOKER, JACK, QUEEN, KING, ACE) using an integer that is randomly generated from a separate class. Would this be possible, and is this good practice?

For example:

I have an integer, say, 3.

I would like to match the integer to the constant value assigned to the enum, in this case my integer 3 would result in being paired to queen.

As the answer below pointed out, enums are automatically stored in an array, so you don't need the cardNumber field unless you were planning on using it for something else. — qwerty

Allen D. Ball Allen D. Ball · Accepted Answer · 2020-08-13T23:30:48

It's as simple as:

int integer = 3;

CARDS card = CARDS.values()[integer - 1];

Note: This works because QUEEN's ordinal is 2 (zero-based).

Use CARDS.valueOf(String) to convert an enum name to CARDS member.

As far as good practice, I suggest a design that takes advantage of the ordinal for ordering and random selection and if you need rank or strength, make those separate attributes (as you did).

You might select a random member with:

CARDS[] deck = CARDS.values();
Random random = new Random();

CARDS card = deck[random.nextInt(deck.length)];

without relying on any specific ordinal value.

Determine the enum value using a value

1 Answers