In this Java 101 tutorial, I’ve explained how interfaces differ from classes, and showed you how to declare, implement, and extend interfaces in your Java programs.

In the package directive’s absence, those classes and interfaces belong to the unnamed package (the directory the JVM regards as the current directory—the directory where a Java program begins ...

The move into functional programming in Java can be intimidating. There were a lot of new interfaces introduced in Java 8 to make working with Streams and lambda expressions possible. But, most of ...