You have a few choices: typeof(IMyInterface).IsAssignableFrom(typeof(MyType)) typeof(MyType).GetInterfaces().Contains(typeof(IMyInterface)) With C# 6 you can use typeof(MyType).GetInterface(nameof(IMyInterface)) != null For a generic interface, it’s a bit different. typeof(MyType).GetInterfaces().Any(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IMyInterface<>))
extends is for extending a class. implements is for implementing an interface The difference between an interface and a regular class is that in an interface you can not implement any of the declared methods. Only the class that “implements” the interface can implement the methods. The C++ equivalent of an interface would be an … Read more
Let’s take your example of a Dog and a Cat class, and let’s illustrate using C#: Both a dog and a cat are animals, specifically, quadruped mammals (animals are waaay too general). Let us assume that you have an abstract class Mammal, for both of them: public abstract class Mammal This base class will probably … Read more
To expand on the answer by bradtgmurray, you may want to make one exception to the pure virtual method list of your interface by adding a virtual destructor. This allows you to pass pointer ownership to another party without exposing the concrete derived class. The destructor doesn’t have to do anything, because the interface doesn’t … Read more
There are some wonderful answers on here to this questions that get into all sorts of great detail about interfaces and loosely coupling code, inversion of control and so on. There are some fairly heady discussions, so I’d like to take the opportunity to break things down a bit for understanding why an interface is … Read more
How about an analogy: when I was in the Air Force, I went to pilot training and became a USAF (US Air Force) pilot. At that point I wasn’t qualified to fly anything, and had to attend aircraft type training. Once I qualified, I was a pilot (Abstract class) and a C-141 pilot (concrete class). … Read more
2019 Update The current answers and the official documentation are outdated. And for those new to TypeScript, the terminology used isn’t clear without examples. Below is a list of up-to-date differences. 1. Objects / Functions Both can be used to describe the shape of an object or a function signature. But the syntax differs. Interface … Read more
Interfaces An interface is a contract: The person writing the interface says, “hey, I accept things looking that way“, and the person using the interface says “OK, the class I write looks that way“. An interface is an empty shell. There are only the signatures of the methods, which implies that the methods do not … Read more