iOS Programming: The Big Nerd Ranch Guide, Second Edition

Core Location

The Core Location framework contains the classes that enable applications to determine the device’s geographical location. No matter what type of iOS device is being used, the Core Location code you write does not change.

The classes in the Core Location framework are all prefixed with CL. In fact, every framework in Cocoa Touch has its own prefix – UIKit classes are prefixed with UI, Foundation classes with NS, etc. Prefixing class names is a convention that prevents namespace collisions. For example, pretend that both Foundation and Core Location have classes called Object. If you wrote an application that used both frameworks, any instantiation of an Object would leave the compiler in a quandary – which Object does this code ...