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.

Here’s an example of how a Function and lambda expression work together: Function<Integer, String> verboseLambda = (Integer x)-> { return Integer. toString (x*x); }; System.

Don't be intimidated by the prospect of doing functional programming in Java. This step-by-step example will help you learn basic Java lambda syntax quickly and effectively.

This is an in-depth java tutorial for beginners. Learn what Java is, how to get started, and how to build basic apps using key concepts!

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 ...