What is the fundamental difference between Inheritance and Polymorphism in software development?

Understanding the Distinctions Between Inheritance and Polymorphism

In software development, grappling with the concepts of inheritance and polymorphism can be perplexing. This article aims to clarify the fundamental differences between the two, addressing the question of their primary distinction.

Inheritance: Extending Class Functionality

Inheritance refers to the ability of a class (known as a child class) to inherit properties and methods from an existing class (known as the parent class). For instance, consider a Person class with properties like name and age. If you create a Student class that extends the Person class, the Student class automatically inherits the properties and methods defined in the Person class.

Polymorphism: Dynamic Method Invocation

Polymorphism, on the other hand, deals with the runtime determination of which method to invoke based on the specific instance of an object. Let's take the example of a Person class with a read method. If we create a Student class that extends Person and provides its own implementation of the read method, the runtime will decide which method to call based on whether the object is a Person or a Student.

Example: Polymorphism in Action

To illustrate polymorphism, consider the following code:

Person p = new Student();
p.read();

In this scenario, the read method defined in the Student class will be invoked even though the object assigned to the variable p is of the Person type. This is because the underlying type of p is Student, and the runtime detects this difference.

Key Difference: Scope and Nature

The primary difference between inheritance and polymorphism lies in their scope and nature. Inheritance establishes a permanent relationship between classes, where a child class shares the characteristics of its parent class. In contrast, polymorphism occurs dynamically at runtime and governs the invocation of methods based on the object's type.

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