分类:
2008-09-12 13:06:53
Enum是enumeration(列举)的简写形式,包含在java.lang包中。熟悉C, , , 或 Pascal人应该对列举有所了解,先看个例子:
public enum Season { winter, spring, summer, fall }
一个enum是定义一组值的对象,它可以包括零个或多个值成员。它是属于enum类型的,一个enum对象中不可有两个或多个相同的属性或值。在次之前的java程序员一般是 用接口的方法实现列举的,如 :
public interface Season {
static winter = 0;
static spring = 1; //etc……
}
引入了enum的java的列举的编写方便了许多,只须定义一个enum型的对象。enum对象的值都回自动获得一个数字值,从0开始,依次递增。看一个比较简单的enum实现的例子:
EnumDemo.java
package net.javagarage.enums;
/*
We can loop over the values we put into the enum
using the values() method.
Note that the enum Seasons is compiled into a
separate unit, called EnumDemo$Seasons.class
*/
public class EnumDemo {
/*declare the enum and add values to it. note that, like in , we don't use a ; to
end this statement and we use commas to separate the values */
private enum Seasons { winter, spring,
summer, fall }
//list the values
public static void main(String[] args) {
for (Seasons s : Seasons.values()){
System.out.println(s);
}
}
}运行上述代码你回得到 以下结果:
winter
spring
summer
fall
[1]