Java enum Class enum summary

Enumeration definition:

An enum is a data type in a computer programming language. Enumeration types: In real-world problems, some variables are scoped to a limited range . For example, there are only seven days in one weeks, 12 months in a year, six courses per week in a class, and so on. If these quantities are described as integers, the character type or other types are obviously inappropriate. For this reason, the C language provides a type called Enum. all possible values are enumerated in the definition of the "enum" type , and the variable value that is described as the "enum" type cannot exceed the defined range . It should be stated that an enumeration type is a basic data type, not a constructed type , because it can no longer be decomposed into any basic type.

Summary of enumeration classes in Java:

1. Enumerations are a special type of data .

2. Enumeration contains enumeration constants and general quantities .

3. Each enumeration constant is an instance object of the current enumeration type.

Look at the code:

1  Public classDemo {2 3      Public Static voidMain (string[] args) {4Person Zhangsan =Person.zhangsan;5Zhangsan.setage (25);6System.out.println (Zhangsaninstanceofperson);//true7     }8 9 }Ten  One enumPerson { A  -Zhangsan ("Zhangsan"), Lisi ("Lisi");//to define enumeration constants with default values -  the     /** - * Normal data type -      */ -     PrivateAtomicinteger count =NewAtomicinteger (); +     Private intAge ; -     PrivateString name; +  A     /** at * Constructors for enumerations -      * @param Age -      * @paramname -      */ -     PrivatePerson (intAge , String name) { -          This. Age =Age ; in          This. Name =name; -System.out.println ("Init count:" +count.addandget (1)); to     } +  -      the     /** *      * @return The Age $      */Panax Notoginseng      Public intGetage () { -         returnAge ; the     } +  A      the     /** +      * @paramAge-The age-to set -      */ $      Public voidSetage (intAge ) { $          This. Age =Age ; -     } -  the      -     /**Wuyi      * @returnThe name the      */ -      PublicString GetName () { Wu         returnname; -     } About  $      -     /** -      * @paramname the name to set -      */ A      Public voidsetName (String name) { +          This. Name =name; the     } -  $}

Java enum Class enum summary