What you need

To follow along with this book, you'll need the following:

• A Mac running OS X El Capitan (10.11), with the latest point release and security patches installed. This is so you can install the latest version of the required development tool: Xcode.
• Xcode 8 or later. Xcode is the main development tool for writing code in Swift. You need Xcode 8 at a minimum, since that version includes Swift 3. You can download the latest version of Xcode for free from the Mac App Store, here: apple.co/1FLn51R.

If you haven't installed the latest version of Xcode, be sure to do that before continuing with the book. The code covered in this book depends on Swift 3 and Xcode 8 — you'll get lost quickly if you try to work with an older version.