public static void queryStudent(ArrayList<Student> list){
        if(list.size()==0){
            System.out.println("当前无学生信息,请添加后再查询");
            return;
        }
        System.out.println("id\t\t姓名\t\t年龄\t\t家庭住址");
        //当代码执行到这里
        for (int i = 0; i < list.size(); i++) {
            Student stu=list.get(i);
            System.out.println(stu.getId()+"\t"+stu.getName()+"\t"+stu.getAge()+"\t"+stu.getAddress());
        }
    }