1. O/O is OK! O/O Benefits Copyright © 2006 Patrick McDermott UC Berkeley Extension pmcdermott@msn.com

2. Holy Graille Re-Use –Instead of re-inventing the wheel, you can build on previous work Maintenance –Most of the cost of a system is in maintenance. It’s claimed O/O reduces maintenance cost. The Far-flung Effect Bottom-line practical benefit: if a company is using it, they won’t hire you if you don’t know it. Camille Bryen Machine for Making Objects in my Mind 1938

3. Deitels 2 Some organizations “indicate that object-oriented programming tends to produce software that is more understandable because it is better organized and has fewer maintenance requirements.” “ Using today’s object-oriented languages, such as C++, Visual Basic.NET, Java and C#, programmers can program in an object-oriented manner that more naturally reflects the way in which they perceive the world. This has resulted in productivity gains.”

4. Ontology Brian Cantwell Smith Origin of Objects, the exploding interest in object-oriented languages: “this turn of events had led computer science squarely into the business of doing research into ontology.” “ A few years ago, at a workshop on the perception of objects, I raised a question about one of the philosophers’ ontological assumptions, which seemed to me altogether too neat. I was concerned about basic issues of object identity—about what makes a newspaper into a single entity as opposed to a large number of separate pieces of paper, what distinguishes the headache that I had this morning from the one I had last night, what it is for Microsoft Word on PCs to be “the same program” as Microsoft Word on the Macintosh.”

5. Kris Jamsa Good Reasons I 1. Ease of design and code reuse —After the code works properly, the use of objects increases your ability to reuse a design or code you created for one application within a second application. 2. Increased reliability —After you have properly tested object libraries, your use of existing (working) code will improve your program’s reliability. 3. Ease of understanding —Object use helps programmers focus on and understand key system components. The use of objects lets designers and programmers focus on the smaller pieces of a system and provides a framework within which designers can focus more on the operations programs perform on the objects, the information objects must store, and other key system components. Jamsa, Kris, PhD, MBA, Jamsa’s C/C++/C# Programmer’s Bible: The Ultimate Guide to C/C++/C# Programming, Second Edition, Albany, New York: Onword Press / Thomson Learning (0-7668-4682-2), 2002, Tip 883, p. 474.

6. Jamsa Good Reasons II 4. Increased abstraction —Abstraction lets designers and programmers “look at the big picture”—­temporarily ignoring underlying details so they can work with system elements they can more easily understand. For example, by focusing only on the word processor objects, the implementation of a word processor can become much less intimidating. 5. Increased encapsulation —Encapsulation groups all the pieces of an object into one neat package. For example, a Book class can combine the functions and data fields a program must have to work with a book. The programmers who are working with the Book class do not need to know each piece of the class, only that they need to use the class within their program. The class, in turn, will bring with it all the necessary pieces. 6. Increased information hiding —Information hiding is the ability for your program to treat a function, procedure, or an object as a “black box,” using the item to perform a specific operation without having to know what goes on inside. For example, your programs can use I/O stream objects for input and output without having to understand how the streams work.