There are 5 sorts of static connascence. Recognizing them and understanding them might help you see extra deeply into your code and the way it works. Many and maybe all of them will probably be acquainted to you, although I guess you by no means actually thought of them to be “coupling.”
Connascence of identify
Connascence of identify happens when two issues need to agree concerning the identify of one thing. That is the weakest type of connascence, or the loosest type of coupling, and the one which we should always aspire to restrict ourselves to. When you declare a process equivalent to
perform DoSomething(): void {
// Code that does one thing
}
Then you need to name it utilizing its identify, on this case DoSomething. When you select the identify, you’re caught with it. Altering the identify of one thing requires modifications elsewhere. If you wish to change the identify of the process, it’s good to change it all over the place that you just’ve known as it. That appears apparent, and naturally this stage of connascence is unavoidable. In truth, it’s fascinating. It’s the bottom stage of coupling we are able to have. If we may restrict our coupling to connascence of identify, we’d be doing extraordinarily properly.
Connascence of sort
Connascence of sort happens when two entities need to agree on the kind of one thing. The obvious instance is the parameters of a way. When you declare a perform as follows:
class SomeClass {
processWidget(aWidget: Widget, aAction: WidgetActionType): boolean {
// Operate logic goes right here
return false; // Instance return worth
}
}
Then any calling code should go a Widget and a WidgetActionType as parameters of the processWidget perform and should settle for a boolean because of this sort.
Connascence of sort isn’t fairly as weak as connascence of identify, however it’s nonetheless thought of a weak and acceptable stage of connascence. Certainly, you couldn’t get alongside with out it, may you? You’ve to have the ability to name a way of a category to get something completed, and it’s not very burdensome to make sure that your sorts match. Most code received’t even work correctly in the event you don’t couple code through connascence of sort. The compilers of a typed language received’t even compile code that isn’t coupled with connascence of sort.
Connascence of which means
Connascence of which means happens when parts should agree on the which means of explicit values. Connascence of which means most frequently happens after we use “magic numbers,” that’s, after we use particular values which have which means in a number of locations.