Studying Object and its methods will give you a more functional understanding of Java inheritance and how it works in your programs: All about Object: Java’s superclass ...

In Java 101: Inheritance in Java, Part 1, you learned how to leverage inheritance for code reuse, by establishing is-a relationships between classes. Composition is a closely related programming ...

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 ...