A class can implement multiple interfaces ... Only functional interfaces can use the lambda feature in Java. Abstract classes with only one abstract method cannot use lambdas.

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 ...

sealed classes can improve effectiveness and clarify the intended usage patterns for developers using the code. Sealed classes in Java represent a significant step forward in the language's ongoing ...