Question

Hey how do I access an arraylist from another class? as in call an objects method inside of the arraylist but from the MasterControlPanel class?. Any help is greatly appreciated. Because the get(0) does not seem to be working.

//example

public class MasterControlPanel{
    public static Building building = new Building();

    public static void main(String[] args) {
        building.rooms.get(0).*whatever*
    }
}

public class Building
{
    public static Rooms rooms[] = new Rooms[4];
    private float outsideTemp;
    ArrayList rooms = new ArrayList();

    rooms.add(*new instance*); 
    rooms.add(*new instance*); 

    public Building() {
    }

}

Answer 1

Add a getter:

public class Building{

public static Rooms roomArray[] = new Rooms[4];
private float outsideTemp;
List<Room> rooms;

public Building(float temp){
    rooms = new ArrayList<Room>();
    rooms.add(new Room()); 
    rooms.add(new Room());
    outsideTemp = temp;
}

public List<Rooms> getRoomList() {
    return this.rooms;
}
}

Then you can do:

public class MasterControlPanel{
    public static Building building = new Building();

    public static void main(String[] args){
    building.getRoomList.get(0).*whatever*

    }
}

Aside: why aren’t you defining the type of your Lists? Also, note that I’ve moved code into the Constructor for this class, and fixed name collisions. Also, why the static array? Things to think about…

Last note: added float to constructor to ensure it’s initialized.