To encapsulate something is to envelope and protect it. Encapsulation is a fundamental facility that every programming language supports at some level. Encapsulation is about hiding implementation details so ideas can be expressed at higher levels and to protect those details from other parts of the system. To me, most fundamentally, encapsulation means hiding implementation …
Continue reading “Quality Code is Encapsulated”
Read MoreI can learn a lot about the kind of coupling in a system by listening to how people talk about testing it. If someone says, “I couldn’t test that without instantiating half the system,” then I know they have some coupling issues. Unfortunately, most systems I have seen—and most systems I know other people have …
Continue reading “Coupling and Testability”
Read MoreWe continue our conversation on code qualities with a discussion of why tight coupling is undesirable. Again, I want to stress, as I did in the last post, that we’re not striving for no coupling in a system. A system with no coupling is a system that does nothing. We want the right kind of …
Continue reading “Pathologies of Tight Coupling”
Read MoreWhile cohesion, which was the subject of the last three posts, is about the internal consistency of a class or method, coupling is a code quality that looks at the relationship between entities. There are two distinct forms of coupling: loose coupling and tight coupling. One is good, the other isn’t—and I always forget which …
Continue reading “Quality Code is Loosely Coupled”
Read MoreI feel like I try to go around and get developers to do little things that will make a big difference in their work. For example, if you need to add some behavior to your system, rather than putting that behavior into some pre-existing entity, you should probably create a new class for that new …
Continue reading “Cohesion and Testability”
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