The main thing to keep in mind is that polymorphism requires an inheritance or an interface implementation. You can see this in the example below, featuring Duke and Juggy: ...

This looks like the Liskov substitution principle that Uncle Bob Martin described: Substitute a derived class (Square) for a base class (Rectangle). From the standpoint of the compiler, the above code ...

Though Java prevents multiple inheritance, some circumstances warrant its use. In this article, author Thomas Hammell illustrates a technique for simulating multiple inheritance in a Web-based ...