The difference between a class and an interface, in this case, is that interfaces don’t keep state. If you attempt multiple inheritance like I have below, the code won’t compile: ...

Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs. Abstract classes ...

Sealed classes make Java an even more powerful and expressive language and set the stage for even more sophisticated techniques such as pattern matching, which we'll explore in a subsequent article. A ...