枚举类enum

Enum类的几个重要有用的方法

1. toString

Size.SMALL.toString(); //返回字符串"SMALL"

2. valueOf

Size s = Enum.valueOf(Size.class, "SMALL"); //将s设置为Size.SMALL

3. ordinal

Size.SMALL.ordinal(); //返回0，返回枚举常量的位置

枚举类型的工作方式

import java.util.*;/** * This program demonstrates enumerated types */enum Size{SMALL("S"), MID("M"), LARGE("L"), EX_LG("XL");private String str;private Size(String data) //构造器在构造枚举常量时被调用{str = data;}public String getStr(){return str;}}public class Test{public static void main(String args[]){Scanner in = new Scanner(System.in);System.out.print("enter a size: SMALL, MID, LARGE, EX_LG:  ");String input = in.next().toUpperCase();in.close();//static Enum valueOf(Class enumClass, String name)返回带指定名称的指定枚举类型的枚举常量Size size = Enum.valueOf(Size.class, input);System.out.println("size=" + size);System.out.println("str=" + size.getStr());if(size == Size.EX_LG){System.out.println("good job -- you paid attention to the fat.");}}}

output:

enter a size: SMALL, MID, LARGE, EX_LG:  smallsize=SMALLstr=S

enter a size: SMALL, MID, LARGE, EX_LG:  ex_lgsize=EX_LGstr=XLgood job -- you paid attention to the fat.