Maybe I have taken too many mock exams? These pattern questions all start looking the same to me. These three patterns have somewhat similar definitions in relation to "coupling" - to the point I don't know what reality is.?? For example - here are some questions I made up: Question 01: What pattern can be used to promote loose coupling? Select one of the following three patterns: Mediator Model View Controller Session Facade Question 02: What pattern can be used to correct tight coupling? Select one of the following three patterns: Mediator Model View Controller Session Facade Question 03: What pattern can be used to prevent tight coupling? Select one of the following three patterns: Mediator Model View Controller Session Facade What are other people's thoughts about this? I was thinking the Mediator pattern is for "promoting loose coupling"(per GoF book), however, the "prevention" and "correction" of tight-coupling doesn't seem clear to me. It seems like any of the three could be a possible answer. thanks! Kevin Thompson
MVC and Session Facade ARE on the exam. There are questions on the exam about loose coupling/tight coupling that have selections like I suggested above. How do I know for a fact that these patterns are on the exam? Becuase I took the exam several months ago and failed, and these patterns were there. I missed the question - because these patterns look alike to me. In addition, there are a number of posts from people here and also on Yahoo saying that they also seen these patterns on exam. Kevin Thompson
Even if you don't know what the patterns are, as long as you understand what 'coupling' is then you will be able to answer the questions. MVC promotes loose coupling - it should be straightforward to change from a html based client to a java (thicker) client. Mediator promotes loose coupling since objects cannot refer directly to each other. MVC does not prevent coupling. If you are trying to add an alternate client to a coupled MVC design then you could use a Facade pattern.