Coming from BASIC

Many programmers learned how to program using Visual Basic or REALbasic, and their transition to Cocoa and Objective-C can be a confusing one.

BASIC (Visual and REAL) environments provide an integrated development environment that makes up the complete workspace. Cocoa splits the development environment into two parts: Interface Builder and Xcode. You use Interface Builder to create the user interface and to tell the user interface the name of the methods to invoke on a particular object, and then you put your control logic into source code edited in Xcode (or TextMate, BBEdit, emacs, or whichever text editor is your favorite).

In BASIC, the user interface items and the code they work with are tightly integrated. You put chunks of code into the buttons and text fields to make them behave the way you want. You can factor this code out into a common class and have the code in the buttons talk to that class, but for the most part, BASIC programming involves putting code on user interface items. If you're not careful, this style can lead to messy programs with the logic scattered across a lot of different items. BASIC programming typically involves changing properties of objects to get them to behave the way you want.