iOS 10 Programming Fundamentals with Swift

Chapter 8. Documentation

Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

Samuel Johnson, Boswell’s Life of Johnson

No aspect of iOS programming is more important than a fluid and nimble relationship with the documentation. There is a huge number of built-in Cocoa classes, with many methods and properties and other details. Apple’s documentation, whatever its flaws, is the definitive official word on how you can expect Cocoa to behave, and on the contractual rules incumbent upon you in working with this massive framework whose inner workings you cannot see directly.

Your primary access to the documentation is in Xcode, through the documentation window (Window → Documentation and API Reference, or Help → Documentation and API Reference, Command-Shift-0). So this chapter starts by talking about the documentation window and, in particular, its class documentation pages.

But there are other forms of documentation and assistance. Quick Help popovers and the Quick Help inspector provide documentation without leaving the code editor. You can examine the code headers, which provide a useful overview and often contain valuable comments; and you can jump quickly to any symbol declaration. Apple provides sample code, and there are lots of additional online resources. This chapter surveys all of that as well.

The Documentation Window

New in Xcode 8, the main documentation is included entirely within Xcode (in compressed form). The ...