Java Enumeration Summary

2. How do I define an enumeration class?

   1 // 4 levels defined 2 enum level{3    a,b,c,d4 }

3. The essence of the enumeration class:

   1 classlevel{2      Public Static FinalLevel A =NewLevel ();3      Public Static FinalLevel B =NewLevel ();4      Public Static FinalLevel C =NewLevel ();5      Public Static FinalLevel D =NewLevel ();6}

4. Enumeration classes can define constructor methods, properties, methods

   1 enumlevel{2A ("85~100", "excellent"),3B ("75~84", "Liang"),4C ("60~74", "Medium"),5D ("Less than 60", "poor");6     PrivateString score;7     PrivateString CType;8     PrivateLevel (String score,string CType) {//the construction method must be private9          This. score =score;Ten          This. CType =CType; One     } A      PublicString Getscore () { -         return  This. Score; -     } the      PublicString Getctpye () { -         return  This. CType; -     } - } +  Public classenumation { -      Public Static voidMain (string[] args) { + System.out.println (Level.a.getscore ()); A System.out.println (Level.a.getctpye ()); atlevel[] ls =level.values (); -     } - } - //Output Results - //85~100 - //Excellent

5. Enum class with abstract method

   1 enumlevel{2A ("85~100"){3 @Override4          PublicString Getctpye () {5             returnExcellent;6         }7     },8B ("75~84") {9 @OverrideTen          PublicString Getctpye () { One             returnGood; A         } -     }, -C ("60~74") { the @Override -          PublicString Getctpye () { -             returnIn; -         } +     }, -D ("Under 60") { + @Override A          PublicString Getctpye () { at             returnPoor; -         } -     }; -     PrivateString score; -     PrivateLevel (String score) { -          This. score =score; in     } -      PublicString Getscore () { to         return  This. Score; +     } -      Public AbstractString Getctpye (); Each object has to override the abstract method the  *}

6. Common methods

   1  Public classenumation {2      Public Static voidMain (string[] args) {3System.out.println (Level.c.name ());//returns the name of the enumeration constant4System.out.println (Level.c.ordinal ());//returns the ordinal of an enumeration constant (subscript starting from 0)5level[] ls = level.values ();//Traversing enumeration Types6          for(Level l:ls) {7 System.out.println (l);8         }9String letter = "B" ; Ten         //returns an enumeration constant of the specified enumeration type with the specified name, if letter is a non-enumerated type throws an exception Java.lang.IllegalArgumentException:No enum constant OneLevel B =level.valueof (letter); A System.out.println (b.b); -     } -}
    　　 

   Output:
   C
   2
   A
   B
   C
   D
   B

Java Enumeration Summary