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 ...

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 ...

Java currently supports only primitive types and object references. Project Valhalla extends this by introducing inline classes which are new types that exhibit some behaviors of both types of value.

As they exist outside the Java heap, the klasses do not require a Java object header, and they are not the same thing as the class objects used in reflection (which are genuine Java objects).

Although Java lacks a true sizeof () equivalent, the Instrumentation interface introduced with J2SE5 can be used to get an estimate of the size of a particular object via its getObjectSize (Object ...

Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.