public static void updateStudent(ArrayList<Student> list){
        System.out.println("修改学生");
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入要修改得学生id");
        String id=sc.next();
        int index=getIndex(list,id);
        if(index==-1){
            System.out.println("要修改的id不存在");
            return;
        }
        Student stu=list.get(index);
        System.out.println("请输入要修改得学生姓名");
        String newName=sc.next();
        stu.setName(newName);

        System.out.println("请输入要修改得学生年龄");
        int newAge=sc.nextInt();
        stu.setAge(newAge);

        System.out.println("请输入要修改得学生地址");
        String newAddress=sc.next();
        stu.setAddress(newAddress);
        System.out.println("修改成功");
    }