Question

I have an abstract class Room which has subclasses Family and Standard.

I have created room = new ArrayList<Room>(); within a Hostel class and a method to add a room to the ArrayList;

public String addRoom(String roomNumber, boolean ensuite)
{
    if  (roomNumber.equals("")) 
        return "Error - Empty name field\n";
    else
    
    room.add( new Room(roomNumber,ensuite) );
    return  "RoomNumber: " + roomNumber + " Ensuite: " + ensuite 
     + "  Has been added to Hostel " + hostelName;
}

However I get the following compile time error;

Room is abstract; cannot be instantiated

I understand that abstract classes cannot be instantiated, but what is the best way to add a room?

Answer 1

You have this error because you are trying to create an instance of abstract class, which is impossible. You have to

room.add(new Family(roomNumber, ensuoute));

or

room.add(new Standard(roomNumber, ensuoute));