The docs seem to cover it pretty well: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/TheBasics.ht

The docs seem to cover it pretty well: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/TheBasics.html#//apple_ref/doc/uid/TP40014097-CH5-XID_428 https://developer.apple.com/library/prerelease/ios/documenta... But the basic idea around optionals is a much better and cleaner way of dealing with possible null (nil) values. Lots of other languages have and are getting optionals.