Object Oriented Programming using Objective-C

• Methods are invoked by sending messages to the object
• Messages will only ask to perform an activity, not the data that it’ll be performed on. Object decides what data it’ll be performed on
• An object can be redefined as receiver to conduct the same activity on a different set of data or a different activity altogether. Receiver is sort of an instance of an object.
• The result of a message can’t be calculated from the message or method name alone; it also depends
  on the object that receives the message
• Using the static storage class designator to limit the scope of names to just the files
  where they’re declared enhances the independence of source modules
• Function names are global; each function must have a unique name (except for those declared static).
• A function is useful only to those who agree to use the same kind of data structures it accepts as arguments. Because it hides its data, an object doesn’t have this problem. This is one of the principal reasons why classes can be reused more easily than functions.
• Must use, Implementation and Interfaces seperately to hide information.

iPhone OS Overview

In Cocoa Touch layer, The UIKit framework provides the visual infrastructure for your application, including classes for windows, views, controls, and the controllers that manage those objects.

IMPORTANT: Start by learning everything about UIKit. Its the start point for any new project.

Help > Show Research Assistant and leave it open on your desktop while you write your code

UIApplication class provides a centralized point of control and coordination for applications running on iPhone OS

Model Object Implementation Guide

Cocoa Fundamentals Guide is the conceptual entry-point
document