Discussions

A Feuerball instance will only act when in the world. So,, it seems pointless for the first action taken to be asking if any of those instances are in the world (of course, the one acting is in the world). It would be much better to have objects it may hit to detect this object instead of the other way around. Tha

I guess this code is in an Actor subclass. To add an object to the world, you need to call the addObject method on the world the actor is in. <Code Omitted>

Ohhh thank you that makes a lot of sense

Thank you so much!

Just to let you know we've now found a solution. I've just swapped out the installers for the new 3.9.0 release on the download page with a version that should correctly request microphone permissions on Mac when you use the Sound Recorder.

Sorry ... not quite so simple. The timer for respawning cannot be in the class of the instance for the actor removed from the world. It's act method will not be called to count the timer down. Since you will only ever have one instance of that actor at any one time, you can have the world run a respawn timer: (in CrabWorld)

Would it not be easier to have the Cactus class objects look for the Bullet class objects and control their own destiny? Here is an example class with a delay timer (a temporary immunity from taking hits for about one second)

One idea is to have invisible "landing" pads for where a player CAN move a piece at that time. When a piece is dragged and released, if on a pad, it is accepted, else it snaps back to its starting place.

From within your subclass of World, you can use the getObjectsAt(int x, int y, Class clss) method. This will return a list of actors of given type at that location. If you don't need the actor itself, just checking if the list is empty is enough: <Code Omitted>otherwise:

Thanks. (sorry for the late reply)

Thank you very much! it worked great and had a better effect than I thought

The code you are showing is only executed when that particular world is created. It does not run when you click on the "Step" or "Run" buttons. The code (lines 3 through 6) needs to be in the act method or a method

After copying all codes into classes in greenfoot, it compiled for me. I did remove some codes, however -- only those related to sounds and images (because I did not have the required files for them. Classes with syntax errors should show with diagonal red stripes through the class icon and lines containing errors should be marked by red at the beginning of the lines. Also, the error within the line may be underlined, however, some syntax errors have these underlines show at places not exactly where the error actually is.

One simple way to handle it is by creating a new type of Actor for the dead ones: