java - 如何创建一个类的不同实例？

Question

我正在制作一个简单的程序，允许人们登记入住和退房酒店(我的 CS 类(class))。

我需要做的是检查一个房间里的人。有四个房间。我怎样才能做到当有人 checkin 时，下一个 checkin 的人将 checkin 房间 2。

我已经有了:

class Hotel {

    Room room1, room2, room3, room4;

    Hotel() {
        room1 = new Room();
        room2 = new Room();
        room3 = new Room();
        room4 = new Room();
    }

    static checkIn() {
        Scanner sc = new Scanner(System.in);
        System.out.print("naam:");
        String invoer2 = sc.nextLine();

        if (room1.guest == null) {      
            room1.guestst = invoer2;
            System.out.println("Guest " + room1.guest + " gets room 1");
            return;
        } else {
            System.out.println("no rom");
        }

        return;                      
    }
}

class Room {
    static int count;
    String guest;

    Room() {
        guest = null;
        count--;
    }

    Room(String newGuest) {
        guest = newGuest;
        count++;
    }
}

class Guest {
    String name;

    Guest(String newName) {
        name = newName;
    }
}

Answer 1

首先，一家酒店有多个房间。根据您目前学到的知识，您应该使用数组来保存所有 Room 实例

Room[] rooms;

Hotel() {
    rooms = new Room[4];
}

或ArrayList

List<Room> rooms;

Hotel() {
    rooms = new ArrayList<Room>();
}

另见:

• > Arrays tutorial
• > Collections tutorial

---

根据您的评论更新:只需检查每个房间是否有客人，直到找到没有客人的房间(就像在现实世界中一样!)。伪:

if there is no guest in room1, then use room1;
else if there is no guest in room2, then use room2;
else if there is no guest in room3, then use room3;
else if there is no guest in room4, then use room4;
else say "sorry, no rooms left!";

顺便说一句，当您使用数组时，这在简单循环中更容易做到。

for each room, check if there is no guest in room, then use room;
if there is no room, then say "sorry, no rooms left!";

哦，当客人离开房间时，别忘了让客人 null。这将使房间符合重新使用的条件。

另见:

• > if-then-else statements
• > for statement