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. Abstract classes ...

For an introduction to Java interfaces, including the difference between classes and interfaces, see my Java 101 tutorial Working with interfaces in Java. You access an enclosed interface by ...

Java SE 15 (Sept 2020) introduces sealed classes as a preview feature.Sealing allows classes and interfaces to have more control over their permitted subtypes; this is useful both for general ...

There are only half a dozen classes you really need to master to become competent in the world of functional programming. The java.util.function package contains well over 40 different components, but ...

According to the JavaDoc, the Consumer interface accepts any type of object as input. The java.util.function.Consumer class has one non-default method named accept which takes a single object as its ...