Java Inheritance
Usharani Bhimavarapu · 2025
In this chapter on Java inheritance, we explore the foundational concept of inheritance, which allows a class (child or subclass) to inherit properties and behaviors (fields and methods) from another class (parent or superclass). We delve into various types of inheritance, including single, multilevel, hierarchical, and hybrid inheritance. The `extends` keyword is introduced as the primary means to establish an inheritance relationship between classes. We also discuss the different types of parent classes, such as abstract and concrete classes. Constructor chaining, facilitated by the `this` and `super` keywords, is examined to illustrate how constructors in a class hierarchy can call each other to ensure proper initialization. Special considerations for private and protected constructors in inheritance contexts are highlighted. The chapter covers how static methods are inherited and how to initialize blocks and constructors in a parent-child relationship. Additionally, we explore the different types of constructor overloading, where constructors in a class have the same name but different parameter lists. Lastly, we introduce the concept of covariant return types, which allows a method in a subclass to return a type that is a subclass of the return type declared in the parent class. This chapter provides a comprehensive understanding of how inheritance enhances code reusability and organization in Java programming.