Practical Object-Oriented Design. 2 ed

 This book assumes that you have at least tried to write object-oriented software. It is not necessary that you feel you succeeded, just that you made the attempt in any object-oriented (OO) language. Chapter 1, “Object-Oriented Design,” contains a brief overview of object-oriented programming (OOP), but its goal is to define common terms, not to teach programming.

 If you want to learn OO design (OOD) but have not yet done any object-oriented programming, at least take a tutorial before reading this book. OOD solves problems; suffering from those problems is very nearly a prerequisite for comprehending these solutions. Experienced programmers may be able to skip this step, but most readers will be happier if they write some OO code before starting this book.

 This book uses Ruby to teach OOD but you do not need to know Ruby to understand the concepts herein. There are many code examples but all are quite straightforward. If you have programmed in any OO language you will find Ruby easy to understand.

 If you come from a statically typed OO language like Java or C++ you have the background necessary to benefit from reading this book. The fact that Ruby is dynamically typed simplifies the syntax of the examples and distills the design ideas to their essence, but every concept in this book can be directly translated to a statically typed OO language.