一个很简单的枚举类:交通信号灯(红、绿、黄),带一个参数:持续时间。
代码如下:
package example; //JHTP Exercise 8.10 //by pandenghuang@163.com /**Write an enum type TrafficLight, whose constants (RED, GREEN, YELLOW) take one parameter— the duration of the light. Write a program to test the TrafficLight enum so that it displays the enum constants and their durations. */ import java.util.EnumSet; enum TrafficLight{ RED(20), GREEN(30), YELLOW(3); private int duration; TrafficLight(int duration) { this.duration = duration; } public int getDuration() { return duration; } } public class TrafficLightTest { public static void main(String[] args) { System.out.println("All Trafic Lights:"); for (TrafficLight tl : TrafficLight.values()) System.out.printf("%-10s%d%n", tl, tl.getDuration()); } }
运行结果:
All Trafic Lights:
RED 20
GREEN 30
YELLOW 3