目录

一、枚举

1.枚举类的特点：

2.枚举类的使用

3、包含属性和方法的枚举类

二、Enum类

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一、枚举

1.枚举类的特点：

使用enum定义的枚举类默认继承了Enum类，其可以实现一个或多个接口

使用enum定义非抽象的枚举类时会使用final修饰，因此枚举类不能派生子类

枚举类的构造方法默认且只能使用private访问修饰符

枚举类的所有实例必须在枚举类的类体第一行显示列出，列出的枚举实例默认使用public static final进行修饰

2.枚举类的使用

enum Week{
    Monday,Tuesday, Wednesday,Thursday,Friday,Saturday,Sunday
}
public class Enum_1 {
    public static void main(String[] args) {
        Week today = Week.Monday;
        System.out.println("today is " + today);
 
        System.out.println("Week枚举类型的所有取值：");
        for (Week week:Week.values()) {
            System.out.println(week);
        }
    }
}
 

3、包含属性和方法的枚举类

enum Weeks{
    //  第一行列举枚举实例
    Monday("星期一"),Tuesday("星期二"),Thursday("星期四"),
    Friday("星期五"),Saturday("星期六"),Sunday("星期日");
    private String name;
    Weeks(String name) {
        this.name = name;
    }
    public String toString(){
        return this.name;
    }
}
 
public class Enum_2 {
    public static void main(String[] args) {
        Weeks today = Weeks.Monday;
        System.out.println("今天是 " + today);
        System.out.println("Weeks.valueOf('Tuesday') = "+Weeks.valueOf("Tuesday"));
        System.out.println("Week枚举类型的所有取值为：");
        for (Weeks week : Weeks.values()) {
            System.out.println(week);
        }
    }
}
 

二、Enum类

enum Season{
    //  第一行列举枚举实例
    Spring("春"),Summer("夏"),Fall("秋"),Winter("冬");
    private String name;
    private Season(String name) {
        this.name = name;
    }
    public String toString(){
        return this.name;
    }
}
 
public class Enum_3 {
    public static void main(String[] args) {
        System.out.println("Season的所有实例：");
        for (Season season : Season.values()) {
            System.out.println(season);
        }
        System.out.println("————————————————————————————");
 
        
        Season s1 = Season.Spring;
        System.out.println(s1);
        System.out.println("————————————————————————————");
 
        
        Season s2 = Season.valueOf(Season.class,"Summer");
        Season s3 = Season.valueOf("Summer");
        System.out.println(s2 + " ----- " +  s2.ordinal());
        System.out.println(s3 + " ----- " +  s3.ordinal());
        System.out.println("————————————————————————————");
 
        
        int compare = s2.compareTo(s1);
        if (compare > 0){
            System.out.println(s1 + "------->" + s2);
        }else{
            System.out.println(s2 + "------->" + s1);
        }
        System.out.println("————————————————————————————");
 
        
        if (s2.equals(s1)){
            System.out.println(s1 + " = " + s2);
        }else{
            System.out.println(s1 + " != " + s2);
        }
        System.out.println("————————————————————————————");
    }
}