案例:
- 有一个学科,学科又分为若个班级
- 整个学科一个大集合
- 若干个班级分为每一个小集合
代码:
import java.util.ArrayList;
import com.heima.bean.Student;
public class Demo5_ArrayListInArrayList {
public static void main(String[] args) {
ArrayList<ArrayList<Student>> list = new ArrayList<>();
ArrayList<Student> class1 = new ArrayList<>();
class1.add(new Student("张三", 23));
class1.add(new Student("李四", 24));
ArrayList<Student> class2 = new ArrayList<>();
class2.add(new Student("王五", 25));
class2.add(new Student("赵六", 26));
list.add(class1);
list.add(class2);
for (ArrayList<Student> c : list) {
for (Student student : c) {
System.out.println(student);
}
}
}
}