Key features in Swift

Paul Hudson    June 11th 2015    @twostraws

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.

• Error handling in Swift 2: try, catch, do and throw – it's been entirely rewritten to be modern, fast and safe, and unless you use only a small subset of the iOS APIs you're going to need to learn about it,
• The guard keyword in Swift 2: early returns made easy – guard takes an if statement and adds extra optional unwrapping power, amongst other things.
• The defer keyword in Swift 2: try/finally done right – if you return from a method at the end or part way through, or if you exit a method by throwing an error, your deferred work will take place.
• Availability checking in Swift 2: backwards compatibility the smart way – great for using if #available to run version-specific code in small blocks.