This translates directly to an interface type in Java. ... Typically, an interface will be shown on a class diagram as having realization relationships with other classes. Figure C: ...

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.

When you run the inner class example, the output would be nine. Java’s Function and lambda expression example. Of course, the whole idea of the functional interface is to incorporate lambda ...