How to study design patterns? [closed]

Answer 1

My suggestion would be a combination of implement a few of them and analyze some implementations of them. For example, within .Net, there are uses of adapter patterns if you look at Data Adapters, as well as a few others if one does a little digging into the framework.

Answer 2

I recommend HeadFirst DesignPattern. Reading the book is not enough, after assimilating the concepts you need to findout the answers for lot of questions arise in your mind and try to findout the real life applications where in these patterns can be used. I am doing the same and started asking questions even those questions look silly.

Answer 3

Design patterns are just tools--kind of like library functions. If you know that they are there and their approximate function, you can go dig them out of a book when needed.

There is nothing magic about design patterns, and any good programmer figured 90% of them out for themselves before any books came out. For the most part I consider the books to be most useful at simply defining names for the various patterns so we can discuss them more easily.

Answer 4

Have you read "Design Patterns Explained", by Allan Shalloway.

This book is very different from other design pattern books because it is not so much a catalog of patterns, but primarily presents a way of decomposing a problem space that maps easily to patterns.

Problems can be decomposed into two parts: things that are common and things that vary. Once this is done, we map the common things to an interface, and the things that vary to an implementation. In essence, many patterns fall into this "pattern".

For example in the Strategy pattern, the common things are expressed as the strategy's context, and the variable parts are expressed as the concrete strategies.

I found this book highly thought provoking in contrast with other pattern books which, for me, have the same degree of excitement as reading a phone book.

Answer 5

Derek Banas made youtube tutorials for desing patterns that I like a lot:

http://www.youtube.com/playlist?list=PLF206E906175C7E07

They can be a little short in time, but his timing and presentation makes them very enjoyful to learn.

Answer 6

The way I learned design patterns is by writing lots of really terrible software. When I was about 12, I have no idea what was good or bad. I just wrote piles of spaghetti code. Over the next 10 years or so, I learned from my mistakes. I discovered what worked and what didn't. I independently invented most of the common design patterns, so when I first heard what design patterns were, I was very excited to learn about them, then very disappointed that it was just a collection of names for things that I already knew intuitively. (that joke about teaching yourself C++ in 10 years isn't actually a joke)

Moral of the story: write lots of code. As others have said, practice, practice, practice. I think until you understand why your current design is bad and go looking for a better way, you won't have a good idea of where to apply various design patterns. Design pattern books should be providing you a refined solution and a common terminology to discuss it with other developers, not a paste-in solution to a problem you don't understand.