Inheritance and Method Overriding in Java: A Comprehensive Guide

Inheritance in Java

Inheritance in Java is a mechanism where one object acquires all the properties and behaviors of another object. Inheritance represents the IS-A relationship, also known as a parent-child relationship.

Using inheritance, you can create a general class that defines common traits for a set of related items. This class can then be inherited by other classes, each adding its unique elements.

The keyword extends defines a new class from an existing class. The existing class is called the parent/base/superclass, and the new class is called the child/derived/subclass.

Here's a breakdown:

• Child classes inherit all members of their parent class.
• Child classes cannot access the private members of the parent class directly.
• To access private variables of the parent class, use accessible parent methods like setters and getters.

Method Overriding in Java

In inheritance, method overriding occurs when a method in the subclass has the same name and parameters as a method in its superclass.

When an overridden method is called, it always refers to the method defined by the subclass. The version of the method defined by the superclass is hidden.

Here are some key points:

• Overriding is not applicable to static methods or variables.
• In the case of variables (static and non-static) and static methods, the method or variable belonging to the reference type is invoked when using a reference type variable.
• Method overriding provides a specific implementation of a method already provided by its superclass.
• Method overriding is used for runtime polymorphism.

Dynamic Method Dispatch

Dynamic method dispatch resolves a call to an overridden method at runtime instead of compile time.

A superclass reference variable can refer to a subclass object. Java uses this to resolve calls to overridden methods at runtime.

When an overridden method is called through a superclass reference, Java determines which version of the method to execute based on the object type at the time of the call. This determination occurs at runtime.