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copied!<p>"Classic" java always used "static final int ANIMAL_CAT = 0;" in cases like this.</p> <p>JDK 1.5 introduced "type-safe enums":</p> <p><a href="http://www.javapractices.com/topic/TopicAction.do?Id=1" rel="noreferrer">http://www.javapractices.com/topic/TopicAction.do?Id=1</a></p> <p>You can now do this (a very common practice):</p> <pre><code>enum Quark { /* * These are called "enum constants". * An enum type has no instances other than those defined by its * enum constants. They are implicitly "public static final". * Each enum constant corresponds to a call to a constructor. * When no args follow an enum constant, then the no-argument constructor * is used to create the corresponding object. */ UP, DOWN, CHARM, STRANGE, BOTTOM, TOP } </code></pre> <p>Or you can do this:</p> <pre><code>/** * Example 2 - adding a constructor to an enum. * * If no constructor is added, then the usual default constructor * is created by the system, and declarations of the * enum constants will correspond to calling this default constructor. */ public enum Lepton { //each constant implicity calls a constructor : ELECTRON(-1, 1.0E-31), NEUTRINO(0, 0.0); /* * This constructor is private. * Legal to declare a non-private constructor, but not legal * to use such a constructor outside the enum. * Can never use "new" with any enum, even inside the enum * class itself. */ private Lepton(int aCharge, double aMass){ //cannot call super ctor here //calls to "this" ctors allowed fCharge = aCharge; fMass = aMass; } final int getCharge() { return fCharge; } final double getMass() { return fMass; } private final int fCharge; private final double fMass; } </code></pre> <p>Here's the official documentation:</p> <p><a href="http://docs.oracle.com/javase/1.5.0/docs/guide/language/enums.html" rel="noreferrer">http://docs.oracle.com/javase/1.5.0/docs/guide/language/enums.html</a></p>

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