Not a bad intro to ObjC message syntax. Even though the article has few mistakes.
Most notably ObjC syntax does not have functions that are called, it has messages that are sent to objects and classes. In the end all messages are "translated" to C function calls to objc_msgSend().
Everything makes sense after you read the proper documentation. Which in this case is http://developer.apple.com/library/mac/documentation/Cocoa/R...