I am aware that the command getWorld().addObject.does work in classA when executed in any method. Moreover, if I replace getX/getY by int-values, the programm states Therefore, the object of classA should exist (as it is inserted via the constructor of the worldclass), and the coordinates should be found by the programm - but obviously it's not working. I think what you want is: getWorld(). However, I've always thought that the constructor of a actor class is executed whenever an object of this class is added to the world. Lets say you want to create an object from the class M圜lass, do this: M圜lass newObject new M圜lass() After this, you can use the newObject for whatever you want. I think I know what it means: this command cannot be executed as the classA-object to which getX()/getY() refers to doesn't exist. Exercise 2.3: Modify your Bee class so that it has a constructor.

ND is the name of the class, i want to create an object from, and NDdum is the class this method is located. void, addObject(Actor object, int x, int y) Add an Actor to the world. Now, take a look at the Greenfoot scenario pictured above: tut-access-p1 (right-click and open the link in a new window or tab). So I want to create a new object, from an another class, at the same spot. Either it has not yet been inserted, or it has been removed.' objects using new, and place the objects in the world using the addObject() method. Class World void, act() Act method for world. A class contains the code for a specific type of object, such as a boat or a pirate. An attempt was made to use the actor's location while it is not in the world. GetWorld().addObject(new classB(), getX(), getY())

Greenfoot addobject class