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MacTech Article: 2703 Developer to Developer

Developer to Developer: Extending Classes with Categories

by Boisy G.Pitre
Mar, 2011 Issue


Article Synopsis

As an object-oriented language, Objective-C gives developers the ability to extend a class through the classical object-oriented model of inheritance. Inheritance is a time-tested means of bringing additional functionality to our classes, and most of the time, it is the appropriate and expedient choice. However, Objective-C has another, and some might say more convenient, technique of extending a class. In this month's Developer to Developer, we'll explore the concept of categories and how we can use this alternative to subclassing to add and extend our own classes.




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