See the Java 101 Java interfaces tutorial for a more in-depth introduction to using interfaces in your Java programs, including where and where not to use default, static, and private methods.

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 ...

Java Supplier interface tutorial. As you can see, the code for the class that implements Java’s Supplier interface is fairly simple. The only requirements are the class declaration and the ...