学生管理系统

需求文档进行分析

switch语句写菜单

switch(choose){

case1:

}

while (true) {
            System.out.println("--------------欢迎来到学生管理系统------------------------");
            System.out.println("1:添加学生");
            System.out.println("2:删除学生");
            System.out.println("3:修改学生");
            System.out.println("4:查询学生");
            System.out.println("5:退出");
            System.out.println("请输入你的选择：");
            Scanner sc = new Scanner(System.in);
            String choose = sc.next();
            switch (choose) {
                case "1"-> System.out.println("添加学生");
                case "2"-> System.out.println("删除学生");
                case "3"-> System.out.println("修改学生");
                case "4"-> System.out.println("查询学生");
                case "5"-> System.out.println("退出");
                default -> System.out.println("没有这个选项");
            }
        }

public static void addStudent(){
        System.out.println("添加学生");
    }
    public static void deleteStudent(){
        System.out.println("删除学生");
    }
    public static void updateStudent(){
        System.out.println("修改学生");
    }
    public static void queryStudent(){
        System.out.println("查询学生");
    }

添加

public static void addStudent(ArrayList<Student> list){
        Student s = new Student();
        System.out.println("添加学生");
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入id");
            String id = sc.next();
            boolean flag = contain(list, id);
            if (flag) {
                System.out.println("请重新输入id");
            }
            else{
                s.setId(id);
                break;
            }
        }

        System.out.println("请输入姓名");
        String name = sc.next();
        s.setName(name);
        System.out.println("请输入年龄");
        int age = sc.nextInt();
        s.setAge(age);
        System.out.println("请输入家庭住址");
        String address=sc.next();
        s.setAddress(address);
        list.add(s);
        System.out.println("添加成功");

    }
//判断id是否唯一
public static boolean contain(ArrayList<Student> list,String id){
        for (int i = 0; i < list.size(); i++) {
            if(list.get(i).getId().equals(id)){
                return true;
            }
        }
        return false;
    }

删除

 public static void deleteStudent(ArrayList<Student> list){
        System.out.println("删除学生");
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要删除的id");
        String id = sc.next();
        int getindex = getindex(list, id);
        if (getindex == -1) {
            System.out.println("id不存在");
        }
        else {
            list.remove(getindex);
            System.out.println("删除成功");
        }

    }

//返回id的索引
public static int getindex(ArrayList<Student> list,String id){
        for (int i = 0; i < list.size(); i++) {
            if(list.get(i).getId().equals(id)){
                return i;
            }
        }
        return -1;
    }

修改

 public static void updateStudent(ArrayList<Student> list){
        System.out.println("修改学生");
        Scanner sc = new Scanner(System.in);

            System.out.println("请输入要修改学生的id");
            String id = sc.next();
            int index = getindex(list, id);
            if (index == -1) {
                System.out.println("id不存在");
                return;
            }
            Student s = list.get(index);
        System.out.println(list.get(index).getName());
        System.out.println("newname");
        String newname = sc.next();
        s.setName(newname);
        System.out.println("newage");
        int newage = sc.nextInt();
        s.setAge(newage);
        System.out.println("newaddress");
        String newaddress = sc.next();
        s.setAddress(newaddress);
        System.out.println("success");

    }