Sách Ebook Holub on Patterns

Chapter 1: Preliminaries—Os(OO) and
Design Patterns 101
Normally a book of this sort would start with a quote from Christopher Alexander, the
architect (of buildings) who came up with the notion of a design pattern. I've found that
though Alexander is a brilliant man who writes wonderful books, his prose can be a bit
opaque at times, so I'll skip the mandatory quote. His ideas launched the entire designpattern
movement, however.
Similarly, the seminal book on design patterns in software is Gamma, Helm, Johnson,
and Vlissides's Design Patterns: Elements of Reusable Object-Oriented Software
(Addison-Wesley, 1995). (The four authors are jokingly called the Gang of Four by most
working designers.) My book wouldn't exist if the Gang-of-Four book hadn't been written,
and I (and OO programmers in general) owe an enormous debt of gratitude to the authors.
Nonetheless, the Gang-of-Four book is a formal academic presentation of patterns, and
most beginners find it too dense to penetrate. At the risk of losing some academic
precision, I'll take a kinder and gentler approach.