Summary

Design patterns have a rich and interesting history. From their origin as tools for helping to describe how to build the structures to allow people to live together, they have grown to be applicable to a number of domains.

It has now been a decade since the seminal work on applying design patterns to programming. Since then, a vast number of new patterns have been developed. Some of these patterns are general-purpose patterns such as those outlined in the GoF book, but a larger number are very specific patterns which are designed for use in a narrow domain.

JavaScript also has an interesting history and is really coming of age. With server-side JavaScript taking off and large JavaScript applications becoming common, there is a need for more diligence in building JavaScript applications. It is rare to see patterns being properly exploited in most modern JavaScript code.

Leaning on the teachings provided by design patterns to build modern JavaScript patterns gives one the best of both worlds. As Isaac Newton famously wrote:

"If I have seen further it is by standing on ye shoulders of Giants."

Patterns give us easily-accessible shoulders on which to stand.

In the next chapter we will look at some techniques for building structure into JavaScript. The inheritance system in JavaScript is unlike that of most other object-oriented languages and that provides us both opportunities and limits. We'll see how to build classes and modules in the JavaScript world.