Use 'class' to Define Enumeration

Java Tutorials - Herong's Tutorial Examples

∟Use 'class' to Define Enumeration

This section provides a tutorial on how to define a set of enumeratin constants use a 'class' declaration statement.

If you don't like to use 'enum' declaration statements, you can use 'class' declaration statement to define an enumeration. Here is an example of "class" declaration statement defining as set of enumeration constants:

/* Season.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
class Season {
   public static Season WINTER = new Season("WINTER");
   public static Season SPRING = new Season("SPRING");
   public static Season SUMMER = new Season("SUMMER");
   public static Season FALL = new Season("FALL");
   private String label = null;
   Season(String label) { this.label = label; }
   public String toString() { return label; }
}

We can see how those enumeration constants behave with this test program:

/* SeasonTest.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
class SeasonTest {
   public static void main(String[] arg) {
      System.out.println("Converting enum constant to string:");
      System.out.println("   Season.WINTER = "+Season.WINTER);
      System.out.println("   Season.SPRING = "+Season.SPRING);
      System.out.println("   Season.SUMMER = "+Season.SUMMER);
      System.out.println("   Season.FALL = "+Season.FALL);

      System.out.println("Getting enum constant class name:");
      String clsName = Season.WINTER.getClass().getName();
      System.out.println("   Season.WINTER.getClass().getName() = "
         +clsName);
   }
}

If you compile SeasonTest.java with Season.java and run SeasonTest.class, you should get:

herong> javac Season.java

herong> javac SeasonTest.java

herong> javac SeasonTest
Converting enum constant to string:
   Season.WINTER = WINTER
   Season.SPRING = SPRING
   Season.SUMMER = SUMMER
   Season.FALL = FALL
Getting enum constant class name:
   Season.WINTER.getClass().getName() = Season