How important are Design Patterns really? [closed]

Answer 1

I would say they definitely are important.

Among the typical reasons (shared vocabulary, not reinventing the wheel) they are a stepping stone to learning good software design. The majority of the design patterns out there start off by programmers with a good sense of OO principles applying what they know to solve a problem, and noticing that other people are coming up with the same solution. If you think of design patterns as a cookbook to solve the current problem you're stuck on, they're not really useful, and this is where you see the "design pattern hammer" come out and complicate designs.

If instead think of it as a window into good object oriented design you start to see how valuable they are, i.e. thinking in terms of the principles behind the design patterns instead of the specific design patterns themselves.

Answer 2

I've seen too many cases of "Small Boy With A Pattern" syndrome. It usually strikes hardest just after a person has read the GoF book for the first time and instantly runs off to see how many of them they can fit into the project they're working on. (Extra points for cramming all 23 into a single project.) They end up with a system that's engineered within an inch of its life and impossible to understand or modify.

Eventually the fever breaks and they settle down enough to use them appropriately. But the damage can be great.

The cautionary tale is the "Core Java EE Patterns" book. It lists a bunch of stuff that addresses "best practices" for EJB 1.0 and 2.0 that are now considered anti-patterns. The EJB 3.0 spec does away with a lot of them. Spring is killing the rest.

Patterns have had their day in the sun, like UML. But the sun is going down on both. I don't think either one has saved the world or delivered on the hype.

Answer 3

Great question! I wast just asking myself that question about a week ago. I use them whenever I can, but I don't really find lots of opportunities to use them. I personally think that the idea of Design Patterns is great. Mechanical engineers and Electronics engineers don't design from scratch, but applying well-understood patterns that among other things allow newbies to stand on the shoulders of the knowledge laid by their predecessors. Design Patterns are a step on the right direction, but much more steps are needed.

Answer 4

I think you miss the point on what a Design Pattern is.

In software engineering, a design pattern is a general reusable solution to a commonly occurring problem in software design.

So design patterns are just a formal language to define common ways to solve software engineering problems. I would think most people are using design patterns without knowing that they are. So these common solutions to software problems can date back a long way, they just hadn't come up with a formal language to describe what they where doing.

I think design patterns are important because they teach you the command ways to solve the problems in the areas that design patterns apply to.

Answer 5

commented Design Patterns are helpful if you are trying to contribute to open source projects... enough said!

Answer 6

Personally, I consider them vastly overhyped and of marginal value. The idea sounds great, but when you get down to it, there's really only a handful that common and useful enough to be worth remembering (and possible to remember).

I'd say their net effect is negative, due to the hideous overengineering perpetrated by people newly enamoured with the concept and trying to cram as many patterns into their code as possible. Perhaps even worse is the Maslow's hammer effect leading to bad design because instead of finding the optimal one, the developer remembered a design pattern that fits (badly).