In this chapter, we got to know some intricacies of object-oriented programming, using the concept of inheritance precisely by creating something called a superclass and subclass and establishing an "is-a" relationship between them. We also discussed the usage of some key aspects, such as overriding a subclass and superclass, data structures, and the protected method. We also got to know how an abstract method works in detail.
In the next chapter, you'll learn about useful Java classes.