JAVA---枚举

1.枚举介绍

 

 enum有隐式继承Enum类，java是单继承。所以不继承其他类，但可以实现接口

1.1自定义枚举

 

 

 

 

 

1.2使用enum关键字实现枚举类

1.2.1注意事项

 

 1.2.2例子

 

1.3enum常用方法

 

 

 

 

 

 

public class Demo2 {
    public static void main(String[] args) {
        season1 spring = season1.SPRING;
        System.out.println(spring.getName());
        //spring.ordinal()输出该枚举对象的编号/次序，从0开始编号
        // SPRING ("春","暖"),SUMMER("夏","热"),what();//0，1，2
        System.out.println(spring.ordinal());//输出0
        //season1.values()含有定义的所有枚举对象
        season1[] values = season1.values();
        for (season1 obj :values) {//增强for遍历一下
            System.out.println(obj);
        }
        season1 spring1 = season1.valueOf("SPRING");
        System.out.println(spring==spring1);
        System.out.println(Arrays.toString(values));
        //[season{name='春', desc='暖'}, season{name='夏', desc='热'}, season{name='null', desc='null'}]
        System.out.println(spring1.compareTo(season1.SUMMER));
    }
}
enum  season1{//使用enum关键字代替class
    //使用枚举要将定义的常量放在最前面
    //SPRING ("春","暖")解读：常量名(实参列表)，有多个常量或对象用逗号隔开
    SPRING ("春","暖"),SUMMER("夏","热"),what();
    //what()走的无参构造，可以不要()
    //定义属性private String name;放在常量后面
    private String name;
    private String desc;
    public String getName() {
        return name;
    }
    public String getDesc() {
        return desc;
    }
    @Override
    public String toString() {
        return "season{" +
                "name='" + name + '\'' +
                ", desc='" + desc + '\'' +
                '}';
    }
    private season1(String name, String desc) {
        this.name = name;
        this.desc = desc;
    }
    season1() {
    }
}

1.4enum实现接口

 

public class Demo3 {

    public static void main(String[] args) {
        weeks[] values = weeks.values();
        System.out.println("==========星期信息如下=====");
        for (Object obj :values) {
            System.out.println(obj);
        }
         weeks.week1.music();
    }
}
interface musicInterFace{
    void music();
}
enum weeks implements musicInterFace {
    week1("星期一"), week2("星期二"), week3("星期三"), week4("星期四"), week5("星期五"), week6("星期六"), week7("星期七");
    @Override
    //实现了musicInterFace接口
    public void music() {
        System.out.println("放一首好听的网易云音乐");
    }
    private String weeks;

    weeks(String week) {
        this.weeks = week;
    }

    weeks() {
    }

    public String getWeeks() {
        return weeks;
    }

    @Override
    public String toString() {
        return weeks;
    }
}