Question

In my work (which is 90% Java but I’m sure this question applies to other languages) I often create two classes that “know about” each other. More concretely, class A imports B, and class B imports class A, and both have member or local variables of the other type.

Is this considered bad design? An anti-pattern if you will?

Answer 1

Here is my take:

• If the two classes belong to the same logical module, then it’s probably fine (still a judgement call of course, with lots of grey areas).
• It’s less fine if the two classes belong to different modules. This creates a circular dependency between modules. I try to avoid that as much as can, preferring a clear hierarchical structure.