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 ...

Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

Object-oriented systems are usually partitioned into layers of related responsibilities and only dependencies in one direction are allowed, from higher layers (more specific, less reusable) to lower ...

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 ...