集合嵌套（一）

ArrayList嵌套ArrayList；

import java.util.ArrayList; public class Test{ public static void main(String[] args){ ArrayList<Student> class01 =new ArrayList<Student>(); //班级一 class01.add(new Student("张三",17)); class01.add(new Student("李四",18)); class01.add(new Student("王五",20)); ArrayList<Student> class02 =new ArrayList<Student>(); //班级二 class02.add(new Student("罗辑",34)); class02.add(new Student("庄颜",22)); class02.add(new Student("云天明",30)); ArrayList<Student> class03 =new ArrayList<Student>(); //班级三 class03.add(new Student("方一凡",18)); class03.add(new Student("乔英子",18)); class03.add(new Student("林磊儿",17)); ArrayList<ArrayList<Student>> school =new ArrayList<ArrayList<Student>>(); //学校 school.add(class01); school.add(class02); school.add(class03); //遍历输出 for(ArrayList<Student> stus:school){ for(Student stu:stus){ System.out.println(stu); } } } }