In Java 101: Inheritance in Java, Part 1, you learned how to leverage inheritance for code reuse, by establishing is-a relationships between classes. Composition is a closely related programming ...

Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.

The more familiar you are with Object and its methods, the more you can do with your Java programs.

It's not good enough to simply use inheritance and apply the rules of polymorphism to your code. To write SOLID code, and properly implement the Liskov substitution principle in Java, your code must ...