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 ...

The release of Java SE 15 in Sept 2020 will introduce "sealed classes" (JEP 360) as a preview feature. A sealed class is a class or interface which restricts which other classes or interfaces may ...

Optimize your own algorithms with standard Java classes. Remove duplicates with Java’s Stream API. The fastest and most efficient way to remove items from a List in Java is to use the distinct method ...

Testing Java Classes. Why, of course, by virtually starting up the Java class and pushing the buttons, so to speak. You test a Java class by calling methods on it from another Java class. The ...

Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.