本帖最后由 jiyixuan 于 2012-4-28 20:02 编辑
举个常用的例子,你要表示星期1-7,你可以用int1-7,但是当你把它作为参数的时候,有时后你就给考虑传入0,8的情况.而且用数字表示还需要相应的注释和文档.
这个时候你定义个一个枚举,名字就叫字面就叫Monday , Tuesday ,....就行,直观,并且值可控。
找到早期的枚举举例程序,您可以看看。- public final class Month{
- private String name;
- private Month (String nm){name=nm;}
- public String toString(){return name;}
- public static final Month
- JAN=new Month("January"),
- FEB=new Month("February"),
- MAR=new Month("March"),
- APR=new Month("April"),
- MAY=new Month("May"),
- JUN=new Month("June"),
- JUL=new Month("July"),
- AUG=new Month("August"),
- SEP=new Month("September"),
- OCT=new Month("October"),
- NOV=new Month("November"),
- DEC=new Month("December");
- public static final Month month[]={
- JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC
- };
- public static final Month number(int ord){
- return month[ord-1];
- }
- //main
- public static void main(String args[]){
- Month m=Month.JAN;
- System.out.println(m);
- m=Month.number(12);
- System.out.println(m);
- System.out.println(m==Month.DEC);
- System.out.println(m.equals(Month.DEC));
- System.out.println(Month.month[3]);
- System.out.println(Month.APR);
- }
- }
复制代码 |