Classes, fields, methods, constructors, and objects are the building blocks of object-based Java applications. This Java tutorial teaches you how to declare classes, describe attributes via fields ...

However, Java refers to class libraries as packages. This article explores packages; I show you how to create packages of classes and interfaces, how to import (that is, ...

In Java, a package can contain other packages, classes, or both. When modeling, you’ll typically have logical packages that serve primarily to organize your model.

Sealed classes make Java an even more powerful and expressive language and set the stage for even more sophisticated techniques such as pattern matching, which we'll explore in a subsequent article. A ...