枚举的常见方法

枚举的常见方法

• int ordinal() 枚举项都有索引，从0开始
• int compareTo(E o)
• String name() 枚举项名称
• String toString()
• <T> T valueOf(Class<T> type,String name)通过字节码对象获取枚举对象

values() 此方法虽然在JDK文档中查找不到，但每个枚举类都具有该方法，它遍历枚举类的所有枚举值非常方便

 

public class Demo01 {

    public static void main(String[] args) {
        //枚举类的常见方法
        //1.获取枚举对象
        Season s1 = Season.SPRING;
        Season s2 = Season.WINTER;
        System.out.println("s1:" + s1.ordinal());
        System.out.println("s2:" + s2.ordinal());
        
        //2.比较枚举[索引相减]
        System.out.println(s1.compareTo(s2));
        
        //3.打印枚举项名称
        System.out.println("s1 name:" + s1.name());
        System.out.println("s1:" + s1.toString());//枚举项名称
        
        //4.通过字节码对象获取枚举对象【没啥用】
        Season s3 = Season.valueOf(Season.class, "SPRING");
        System.out.println("s3:" + s3);
        
        //5.类方法，.values() 返回枚举数组
        System.out.println("枚举的遍历");
        Season[] seasons = Season.values();
        for(Season s : seasons){
            System.out.println(s);
        }
    }
}

enum Season{
    SPRING,SUMMER,AUTUMN,WINTER;
}