Learn the difference between classes and interfaces once and for all, then get started declaring, implementing, ... For example, Cloneable (see Inheritance in Java, Part 2) ...

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 ...

Twenty-three years ago, in his Design Principles and Design Patterns article, Robert "Uncle Bob" Martin boiled down the Liskov substitution principle to the idea that "derived classes should be ...

For an introduction to Java interfaces, including the difference between classes and interfaces, see my Java 101 tutorial Working with interfaces in Java. Nesting interfaces in classes Java lets ...