By focusing on Java interfaces instead of classes, you can minimize the number of references to class names in your source code.

Say you’re modelling a car. If you’re modeling in plain old Java, you might have an interface member on the Car class to reference an Engine interface, as shown in Listing 1. Listing 1.

This post explains how to use classes in Java to build objects and organize your code. Also learn: constructors, static methods, and more!