java - 与面向对象方法的斗争

Question

我无法弄清楚 getExits() 需要什么才能获得问题所请求的输出。

//构造函数

public class Room {

    private String name;
    private String description;
    private Room north;
    private Room east;
    private Room south;
    private Room west;

    public Room (String name, String description){
        this.name = name;
        this.description = description;
    }

    public Room getEast(){
        return this.east;
    }

    public String getExits (){
        //
    }   

    public String getName(){
        return this.name;
    }

    public Room getNorth(){
        return this.north;
    }

    public Room getWest(){
        return this.west;
    }

    public Room getSouth(){
        return this.south;
    }

    public void setExits (Room n, Room e, Room w, Room s){
        this.north = n;
        this.east = e;
        this.west = w;
        this.south = s;
    }

    public String toString(){
        return String.format("%s\n%s\n%s", this.name, this.description,getExits());
    }
}

//主要方法

public class Tester{

    public static void main(String []args){

        Room hall = new Room ("Hall", "It's Dark");
        Room bed = new Room ("Bed", "Tiny Room");
        Room bath = new Room ("Bath", "Toilets here");
        Room dine = new Room ("Dine", "Table and chairs");
        hall.setExits(bed, bath, dine, null);

        System.out.println(hall);

    }
}

预期输出:

Hall
It's Dark
North: Dine
East: Bath
West: Dining

Answer 1

获得您想要的内容的“面向对象”方法是重写 Room 类中的 toString() 方法，以便它返回名称房间的。

然后修改 getExits()，如下所示:

public String getExits (){
    StringBuilder sb = new StringBuilder();
    if(this.north != null) sb.append(this.north.toString()).append(" North") else sb.append("No Exit for: North");
    ...

    return sb.toString();
}

...

public class Room {
    private String name;

    ...

    @Override
    public String toString() {
        return this.name;
    }
}