How to reference variables that haven't been initialized yet?

Question

Say I have this setup:

public class Game
{
    public static World World;
    public static Camera Camera;
    public static Player Player;

    public Game()
    {
        World = new World();
        Camera = new Camera();
        Player = new Player();
    }
}

In the camera constructor I use the world object to position the camera, however I also need to access the camera in the world constructor. I cant just use Main.Camera because it hasn't been initialized yet. How do I solve this issue? Is there a programming pattern that I can use to avoid this circular dependency problem?

Answer 1

Just change the initialization order

public class Game
{
    public static World World;
    public static Camera Camera;
    public static Player Player;

    public Game()
    {
        Camera = new Camera();
        World = new World(Camera);
        Player = new Player();
    }
}

If there's a mutual dependence (both depend on each other), you have a problem in your design (circular dependency anti-pattern). You'll probably need to rethink your design. Try not to make a "global object" that holds the state of everything. That's also a design anti-pattern. You need to give details (in a separate question) in order for specific tips.