I already wrote overviews of all the new features of Swift 2 and the new features in iOS 9, but I wanted to get into more depth with some of the Swift 2 language changes so you could start getting to grips with it.
So, I wrote four short articles explaining four key new features in Swift 2 syntax: try catch error handling, guard, defer and API availability checking.
You can work through them in any order you want – enjoy!
UPDATE: I put together a huge and free collection of Swift example code, so if you're upgrading your code you should definitely check it out.
ifstatement and adds extra optional unwrapping power, amongst other things.
if #availableto run version-specific code in small blocks.
Paul Hudson is the creator of Hacking with Swift, the most comprehensive series of Swift books in the world. He's also the editor of Swift Developer News, the maintainer of the Swift Knowledge Base, and Mario Kart world champion. OK, so that last part isn't true. If you're curious you can learn more here.
Become a Swift expert
I wrote a book called Pro Swift that's dedicated to helping you master the Swift language, and it includes seven hours of video demonstrating each technique!