Chapter 7. Foundation Value Classes

Objective-C makes it easy to use standard C types like int, float, and char, but that doesn’t mean they’re always your best options. Cocoa provides actual classes for storing common types of data like numbers and strings. These are informally called value classes, or Foundation value classes.

This is a good time for me to explain that “Cocoa” can actually mean two separate things. Most people use it very broadly to describe an overall ecosystem to write apps for Mac, iPhone, iPod touch, and iPad. Some veteran Mac programmers think of Cocoa specifically as an umbrella framework, which is a framework that contains other frameworks. Whichever definition you prefer, you should understand what each refers to. The Cocoa framework itself encapsulates three separate frameworks: Foundation, AppKit, and Core Data: