As a courtesy, this is a full free rendering of my book, Programming iOS 6, by Matt Neuburg. Copyright 2013 Matt Neuburg. Please note that this edition is outdated; the current books are iOS 10 Programming Fundamentals with Swift and Programming iOS 10. If my work has been of help to you, please consider purchasing one or both of them. Thank you!
Apple has provided a vast toolbox for programming iOS to make an app come to life and behave the way you want it to. That toolbox is the API (application programming interface). To use the API, you must speak the API’s language. That language, for the most part, is Objective-C, which itself is built on top of C; some pieces of the API use C itself. This part of the book instructs you in the basics of these languages:
super, key–value coding, and properties.
We’ll return in Part III. Cocoa to a description of further aspects of the Objective-C language — those that are particularly bound up with the Cocoa frameworks.