It is, but you'll still need to learn about the memory management in objective-C (retain / release and such, although that's been made a lot easier over the years, pushing it back to being background knowledge) and - perhaps more importantly than the actual language - the frameworks, environment and tooling (Foundation, UIKit, iOS application basics / lifecycle, view hierarchy, XCode, Interface Builder, and background knowledge like accessibility and such).

But yeah, go with Swift, it's closer to Java than Objective-C is.