Inheritance

What is Inheritance?
In Java, inheritance is a fundamental concept in object-oriented programming that allows a class (called a subclass or child class) to inherit properties and behaviors (fields
and methods) from another class (called a superclass or parent class). This promotes code reusability and establishes a hierarchical relationship between classes.

Types of Inheritance:
Single Inheritance: A subclass inherits from a single superclass.
Multilevel Inheritance: A subclass inherits from a superclass, and then another subclass inherits from this subclass, forming a chain.
Hierarchical Inheritance: Multiple subclasses inherit from a single superclass.
Multiple Inheritance (Through Interfaces): A class implements multiple interfaces. Java does not support multiple inheritance with classes to avoid ambiguity but
allows it through interfaces.
Hybrid Inheritance: A combination of two or more types of inheritance. In Java, this is achieved through interfaces.

Use of Inheritance:
Code Reusability – Avoid duplication by inheriting shared code from a parent class.
Method Overriding – Enable polymorphism by allowing subclasses to override parent class behavior at runtime.
Abstraction – Hide internal implementation and expose only the necessary interface.
Extensibility & Maintenance – Easier to extend behavior in derived classes and maintain large systems.
Hierarchical Modeling – Represent real-world hierarchical relationships (e.g., Animal → Dog, Cat, etc.)
Polymorphism via Subtyping – Treat subclasses as instances of their superclass, enabling flexible and interchangeable code.
Note—overuse or deep inheritance hierarchies can introduce complexity, tight coupling, and the fragile base class problem.

How inheritance works?
Syntax: Use the extends keyword between class definitions.
class Superclass { ... }
class Subclass extends Superclass { ... }
Inheritance Chain: A subclass inherits all non-private fields and methods from its superclass and can:
Override parent methods
Add new fields/methods
Call super to access overridden members or superclass constructors
Object as Root: Every class in Java (unless explicitly subclassing another) implicitly inherits from java.lang. Object—the root of the class hierarchy
Interfaces for Multiple/Hybrid Patterns: Since Java doesn't allow multiple class inheritance, interfaces are used to simulate it.
A class can implement multiple interfaces, achieving similar flexibility without ambiguity.

Summary:
Inheritance is a powerful tool for code reuse, polymorphism, and modeling "is-a" relationships in Java.
Java supports single, multilevel, and hierarchical inheritance out of the box.
Patterns like multiple and hybrid inheritance are not supported via classes but can be achieved using interfaces.
Use inheritance thoughtfully—consider composition for flexibility and to avoid complex hierarchies.