Java enum explanation

Enum

An enum is a concept introduced by jdk1.5. The value of the enum type is actually represented by the object constructed at run time. When defining an enum, the compiler will do something for us by default:

1. All enum classes inherit the enum (enum default implementation comparable and Serializable interface) by default, so enum classes cannot inherit other classes (Java single inheritance);
2. All enum classes are final and cannot have sub-classes
3. All defined enumeration constants that generate public static final constants in the defined enumeration class

Note : Switch uses the equal () method by default when judging whether it is equal

custom enum Types :

 Public enumenumtest{Yahoo ("Www.yaho.com"), Baidu ("Www.baidu.com"), Google ("www.google.com");//Note that if there is a custom method, the last enumeration value is required;    PrivateString name;//The construction method must be private or friendly    Private enumtest(String name) { This. name=name; } PublicStringGetName()    {returnName }    }in the//main function      Public Static void Main(string[] args) {System. out. println (EnumTest.Baidu.getName ()); Output Baidu's website

Enum-related tool classes

enumweekday{Mon,tue,wen}enumenumnetwork{Yahoo, Baidu, Google} Public classTest { Public Static void Main(string[] args) { for(WeekDay day:WeekDay.values ()) {System. out. println (day); }//enumset internal through Bit-vector implementation         for(WeekDay Day:EnumSet.range (Weekday.mon,weekday.wen)) {System. out. println (day); }//Note the difference between ENUMMAP and general map usageEnummap<weekday,enumnetwork> map=NewEnummap<weekday, enumnetwork> (Weekday.class); for(intI=0; I<weekday.values (). length;i++) {map.put (Weekday.values () [I],enumnetwork.values () [i]); } System. out. println (Map.Get(Weekday.mon)); }}

Java enum detailed