Abstract classes and interfaces in Java serve fundamentally different purposes ... Can be implemented with the implements keyword. An interface can also extend interfaces. Can only be extended.

We will focus on the relationship between polymorphism and Java ... or an interface implementation. You can see this in the example below, featuring Duke and Juggy: public abstract class ...

With a Java lambda expression, the object type isn’t required on the left hand side, and if the lambda expression is one line long, both the brackets and the return keyword can ... models designed ...