接口,数组,方法调用关系

3

验证

1

满足条件继续执行setLight(ls[1])

false

结束

进入for循环

package _2018年5月17日_8;interface Light {\tvoid shine();}class RedLight implements Light {\tpublic void shine() {\t\tSystem.out.println(\"Red Light shine in Red\");\t}}class YellowLight implements Light {\tpublic void shine() {\t\tSystem.out.println(\"Yellow Light shine in Yellow\");\t}}class GreenLight implements Light {\tpublic void shine() {\t\tSystem.out.println(\"Green Light shine in Green\");\t}}class Lamp {\tprivate Light light;\tpublic void setLight(Light light) {\t\tthis.light = light;\t}\tpublic void on() {\t\tlight.shine();\t}}public class TestLamp {\tpublic static void main(String args[]) {\t\tLight[] ls = new Light[3];\t\tls[0] = new RedLight();\t\tls[1] = new YellowLight();\t\tls[2] = new GreenLight();\t\tLamp lamp = new Lamp();\t\tfor (int i = 0; i ls.length; i++) {\t\t\tlamp.setLight(ls[i]);\t\t\tlamp.on();\t\t}\t}}

i ls.length;

开始

true

之后i ls.length;判定失效退出循环.程序结束

lamp.setLight(ls[i]);

int i = 0;

2

满足条件继续执行setLight(ls[2])

4

lamp.on();

6

i++;

5

数组也是对象

退出for循环

最终输出