Java枚举

目录

枚举引出

自定义枚举

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枚举引出

自定义枚举 package com.edu.eum; public class eum01 { public static void main(String[] args) { //使用 Season spring = new Season("春天","温暖"); Season winter = new Season("冬天","寒冷"); } } //自定义枚举 /* 1、构造器私钥化，目的防止直接new对象出来 2、去掉set相关方法，防止属性被修改 3、在Season内部创建固定对象 4、优化可以再加入一个final 5、枚举对象名要全部大写 */ class Season{ private String name; private String desc; //定义固定对象 public static final Season spring = new Season("春天","温暖"); public static Season winter = new Season("冬天","温暖"); private Season(String name, String desc) { this.name = name; this.desc = desc; } public String getName() { return name; } public String getDesc() { return desc; } } //1、使用关键字enum //2、直接SPRINT("春天","温暖"),有多个用,间隔 //3、常量对象要写在最前面 enum Season02{ SPRINT("春天","温暖"), WINTER("春天","温暖"); private String name; private String desc; private Season02(String name, String desc) { this.name = name; this.desc = desc; } public String getName() { return name; } public String getDesc() { return desc; } }

Enum成员方法 package com.edu.eum; public class enum04 { public static void main(String[] args) { Season02 spring = Season02.SPRING; //输出枚举对象的名称 System.out.println(spring.name()); //输出枚举对象的次序 System.out.println(spring.ordinal()); //返回数组Season02[],含有枚举类定义的所有枚举对象 Season02[] values = Season02.values(); for (Season02 season: values){ System.out.println(season); } //valueOf,将字符串转换为枚举对象，会在定义的对象中匹配已有的常量名，如果没有则报错 Season02 spring01 = Season02.valueOf("SPRING"); System.out.println("spring01="+spring01); //比较两个枚举常量的位置号,相减 System.out.println(Season02.SPRING pareTo(Season02.WINTER)); } }