Use Java's extends keyword to derive a child class from a parent class, invoke parent class constructors and methods, override methods, and more.

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.

Part 6: Use interfaces for safe multiple inheritance and a great deal more Part 7: Learn about Java’s many shapes and find out how to accommodate generalities in your class hierarchies Interfaces ...