What are the two options that come with the core animations beginAnnimations method?

Question

I was wondering what they mean by:

[CustomView beginAnimations:@"whatIsThis" context:whatIsThis];  

I am just wondering what those who things do and how I would use them?
Please help!

Answer 1

They are basically application-specific helper objects. animationID is used to distinguish between the different animations (that could be happening around the same time). context is additional object that gets passed to the delegates and listeners of the animation status. Both are optional, and passing nil should work.

From documentation:

animationID

Application-supplied identifier for the animations within a block that is passed to the animation delegate messages—the selectors set using the setAnimationWillStartSelector: and setAnimationDidStopSelector: methods.

context

Additional application-supplied information that is passed to the animation delegate messages—the selectors set using the setAnimationWillStartSelector: and setAnimationDidStopSelector: methods.