Revolutionary

I have heard numerous accounts from programmers of varying experience levels on how this particular book and set of concepts changed the way they approach object-oriented software. Object-oriented software is about object interaction, implementation is trivial in a system where a reasonable framework is set.

Good object-oriented design, it is true, existed before Design Patterns was introduced, but it is the way object-oriented design was given a set of commonly agreed intuitive names of generic object traits that this piece of holy software scripture earned its place in the 5-star-league. By discussing and using agreed concepts, the processes involved with design, implementation and refactoring can be exposed to a much broader audience, because applying these naming conventions in code implies desired functionality. The approachable, yet rigorously thought-out guidelines in this book further makes reviewing code more efficient because comparison against tested design approaches can be utilized, pointing out many common pitfalls.

A word of caution. This work is very inspirational, and junior level programmers might, upon leafing through this book, emerge even too enthusiastic on applying generic design on systems where simpler approaches would be more logical.

The classic, and still the best

From all other people's reviews, you have already known this is the classic text on the subject of design patterns. This is indisputable so I don't need to waste time trying to prove it again.

However, I would like to say something to those readers who are totally new to design patterns and C++/Smalltalk -- please do not be intimidated by the seemingly terse, dry and difficult style of this book. Since I myself am new to the world of design patterns, I would like to share with you my own experience and hope you can make a better decision when you pick your design patterns book.

"Design Patterns" is the classic text; its style is academic-oriented, rigorous, and terse. Unlike most popular computer books, you will find reading this book takes a lot of thinking, for each paragraph or even each sentence. Most examples used in this book are adapted from real world systems popular many years ago, so you will likely find you're not familiar with them at all. Moreover, some examples are related to GUI programming, so if you're mainly programming for backend, you will probably feel it's tough to understand some of the examples. Most code example in the book is written in C++ (some in Smalltalk.) If you're a Java programmer and have limited knowledge in C++, it might take you some time to guess what certain C++ syntax means.

These all seem to be negative comment, but my conclusion is to the contrary -- this is the BEST book in the area, and you should read it despite of all the issues I mentioned above. I started my design pattern learning by using a couple of other books, such as "Java Design Patterns: A Tutorial", "Design Patterns Explained: A New Perspective on Object-Oriented Design", and "Applied Java Patterns". I chose these books mainly because they seem to be much easier to understand than "Design Patterns". However, after spending time in these alternative books, I found none of them offers the accuracy and depth as "Design Patterns". Often, after I read a chapter of the "easy" book, I feel I am still kind of lost. I seem to have understood the pattern I just learned, but then I feel it's not quite so. I guess I only learned the pattern in a superficial way, with little depth, and without being part of "big picture." Later, I turned to the classic, "Design Patterns". I forced myself to sit down and try to understand the authors' terse and rigorous writing and their unfamiliar examples. Gradually I found I was getting used to the style and the examples, and I actually started to learn much more from this book than from others. After reading half-way through the book, I felt the rigorous style is actually a big plus for this book, because I can get more accurate and in-depth information.

Therefore, I strongly suggest that you buy and read this book, even if you feel it's difficult to read. Your effort will pay off eventually. Use other books as reference only.

Fall asleep while reading this book

There is nothing new here for an experienced developer. It MAY be useful for fresh graduates but I am not sure. It would be more appropriate for designers to come up with real patterns that solve real problems, not just follow patterns stated in this book, which are mostly over-kill or far away from real world. Can't understand why so many people gave it high ratings, and even more people talking about patterns with so much proud.