If you're comfortable writing object-oriented code in Python and PHP, you should be fine. The object-oriented parts of Swift are thoroughly ordinary. One major

If you're comfortable writing object-oriented code in Python and PHP, you should be fine. The object-oriented parts of Swift are thoroughly ordinary. One major concept you will want to become comfortable with (that doesn't really exist in dynamic languages AFAIK) is the concept of protocols: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Protocols.html https://developer.apple.com/library/ios/documentation/Swift/... If you're not comfortable with anonymous functions and closures, I'd recommend getting familiar with them as well, since they play a major role later on in the course.