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.

Create packages, import packaged classes and interfaces into your programs, move packages, and encapsulate them in jar files.