I'm just getting started with Swift, so I may be missing out on some awesome things yet and I do have some catching up to do on the language, but this is nice - especially compared to Objective-C.
If you need to print out the contents of a variable in Objectice-C you'd do:
NSString *string = @"Hello world"; NSLog("string = %@", string)
But in Swift, you can simply do:
let string = "Hello world" // Already better println("string = \(string)")