We will focus on the relationship between polymorphism and Java inheritance. The main thing to keep in mind is that polymorphism requires an inheritance or an interface implementation. You can see ...

Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.

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 ...

Now, we turn our focus to the mothership of the Java class inheritance hierarchy, java.lang.Object. What you’ll learn in this Java tutorial ...