cohesion

What are Cohesion and Decoupling? I found information about coupling but not about decoupling. ant That article from Aaron is very good for understanding, also I'd recommend that you read manning publications Spring in Action book, they give very good examples on how the spring solves that problem it will definitely improve your understanding of this. EDIT : I came accross this in this great book called Growing object oriented software guided by tests : Coupling : Elements are coupled if a change in one forces a change in the other. For example, if two classes inherit from a common parent,

I am building an applications in .net/c#/Entity Framework that uses a layered architecture. The applications interface to the outside world is a WCF service Layer. Underneath this layer I have the BL, Shared Library and the DAL. Now, in order to make the business logic in my application testable, I am trying to introduce separation of concerns, loose coupling and high cohesion in order to be able to inject dependencies while testing. I need some pointers as to if my approach described below is good enough or if I should be decoupling the code even further. The following code snippet is used to

The Law of Demeter indicates that you should only speak to objects that you know about directly. That is, do not perform method chaining to talk to other objects. When you do so, you are establishing improper linkages with the intermediary objects, inappropriately coupling your code to other code. That's bad. The solution would be for the class you do know about to essentially expose simple wrappers that delegate the responsibility to the object it has the relationship with. That's good. But, that seems to result in the class having low cohesion . No longer is it simply responsible for

I'm learning computer programming and at several places I've stumbled upon the concept of cohesion and I understand that it is desirable for a software to have "high cohesion" but what does it mean? I'm a Java, C and Python programmer learning C++ from the book C++ Primer which mentions cohesion without having it in the index, could you point me to some links about this topic? I did not find the wikipedia page about computer science cohesion informative since it just says it's a qualitative measure and doesn't give real code examples. High cohesion is when you have a class that does a well