Swift has an interesting grab bag of features that it looks like the language designers decided to toss in.
- Explicit methods for having 'no value' instead of using null. This means that you can bypass the need that Java has for Double vs double, etc..
- Enhanced for loops that try to support more expressiveness in terms of what to iterate over
- Support for more advance switch statements, with no default fall through (a cause of bugs for decades), but which supports
For a greater introduction to swift the best place is of course Apple's Swift introduction. It covers the basics of the language, but so far in my brief experiences with Swift there are some gotchas that I have found which were not immediately obvious from the book.