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Which is more suitable for static data - final char or enum?

Regarding my Java poker program, would it be a smart decision to choose enum over chars and ints?

As far as I can tell, assigning a separate integer char value has the advantage of ease of use of mathematical operators when it comes to comparing map values ​​to determine the winner. However, this may be possible with transfers, if so I do not know.

Please can someone explain me adv / negative?

My first option to declare card ranks is to enumerate:

public enum Rank { DEUCE (1), THREE (2), FOUR (3), FIVE (4), SIX (5), SEVEN (6), EIGHT (7), NINE (8), TEN (9), JACK (10), QUEEN (11), KING (12), ACE (13) } public enum Suit { CLUBS (1), DIAMONDS (2), HEARTS (3), SPADES (4) }

My second option is static trailing characters with assigned int values ​​as such:

  public static final char ACE = 'A'; public static final char TWO = '2'; public static final char THREE = '3'; public static final char FOUR = '4'; public static final char FIVE = '5'; public static final char SIX = '6'; public static final char SEVEN = '7'; public static final char EIGHT = '8'; public static final char NINE = '9'; public static final char TEN = 'T'; public static final char JACK = 'J'; public static final char QUEEN = 'Q'; public static final char KING = 'K'; public Rank (char c) { switch (c) { case TWO: _val = 0; break; case THREE: _val = 1; break; case FOUR: _val = 2; break; case FIVE: _val = 3; break; case SIX: _val = 4; break; case SEVEN: _val = 5; break; case EIGHT: _val = 6; break; case NINE: _val = 7; break; case 'T': _val = 8; break; case 'J': _val = 9; break; case 'Q': _val = 10; break; case 'K': _val = 11; break; case 'A': _val = 12; break; default: _val = -1; } }

Thanks!

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4 answers

I would prefer Enum . The code looks cleaner and the IDEs can help you avoid the case of switch .

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I suggest you read Point 30: Use enumerations instead of int constants from Effective Java by Joshua Bloch. This explains the many benefits of using enumerations on int constants.

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Use enumerations. Because of:

  • Style
  • - they look better and cleaner.
  • IDE Integration - IDE may request correct input
  • methods can be transferred by listings that automatically filter with a range check (see below).
  • enums may have methods for returning values ​​and / or performing calculations
  • the data you are dealing with has a certain range of values ​​that will never change, so defining an enumeration instance for each value makes sense

Consider this method:

 public static char addCards(char a, char b);

I can call it with invalid input

 addCards('x', '$');

There is no built-in range check with char . But with transfers it is provided free of charge.


As for your ranking problem, with listings you can just do it

 Rank r1, r2; boolean r1RankedHigherThanR2 = r1.ordinal() > r2.ordinal();

The order you define for enum instances is enough to convey the ranking order.

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Recursions have an ordinal (based on 0). Therefore, you can use them for ranking, and you probably shouldn't duplicate this. e.g. KING.ordinal ().

Also, aside, poker suits do not have a rank - you have your suits in order of rank of the bridge.

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