If you mean you want to check the class of the world the actor is in, the code you have written above is fine. If it doesn't seem to be working it's because something is wrong elsewhere in your code.

I don't see anything wrong in my coding; the statement is at the start of the act() method. The code in the if statement just doesn't activate for some reason, and I just can't figure it out! (I forgot to publish the source code to my game, so I can't give you the entire code at this time).

Are you setting this image to an actor? is that actor in the world? (of course if you are setting the image of the actor that this class is executing the act method on, then yes; otherwise, maybe it is not the actor you see in the world whose image is changing)

I guess nobody can figure it out unless you show them the code ;)

The actor is not in a any world when the constructor is being executed -- the actor has to be created before it can be placed in a world. Override the 'addedToWorld(World)' method and move the code into it.

Aw....... *facepalm* OK, thank you!