Is it possible to define an anonymous selector in Objective-C?

Answer 1

Unfortunately, no. The idea is self-contradictory — a selector is a name. That's all it is. It doesn't define any functionality.

Objective-C didn't have any kind of anonymous function until just recently when blocks were introduced into Mac OS X. It's possible to use them on the iPhone through Plausible Blocks, but they're still not integrated into the APIs there.