Last Updated on July 19, 2023 by Mayank Dham
Object-oriented programming (OOP) is a popular paradigm used in many programming languages, including Java, C++, and Python. Two fundamental concepts in OOP are inheritance and polymorphism. While they are closely related, they serve different purposes and have distinct characteristics. In this article, we will delve into the difference between inheritance and polymorphism, exploring their definitions, use cases, and how they contribute to building flexible and extensible code.
What is Inheritance?
Inheritance is a mechanism that allows a class to inherit properties and behaviors from another class, known as the superclass or base class. The class that inherits these properties is called the subclass or derived class. Inheritance promotes code reuse, as the subclass automatically gains access to the attributes and methods of its superclass. It establishes an "is-a" relationship, where the subclass is a more specific type of superclass.
Types of Inheritance are
Five Types of Inheritance are given below:
- Single inheritance
- Multi-level inheritance
- Multiple inheritance
- Hybrid inheritance
- Hierarchical inheritance
What is Polymorphism?
Polymorphism, on the other hand, is the ability of objects of different classes to respond differently to the same message or method call. It allows objects to be treated as instances of their own class or as instances of any of their ancestor classes. Polymorphism is achieved through method overriding and method overloading. Method overriding involves providing a different implementation of a method in the subclass, while method overloading allows multiple methods with the same name but different parameters in the same class or hierarchy.
Types of Polymorphism are
Generally, there are two types of Polymorphism:
- Compile-time polymorphism (Method overloading)
- Run-time polymorphism (Method Overriding)
Difference between inheritance and polymorphism
Difference between inheritance and polymorphism in tabular form are discussed below:
| Category | Inheritance | Polymorphism |
|---|---|---|
| Definition | A mechanism where a class inherits properties and behaviors from another class (superclass). | Ability of objects of different classes to respond differently to the same method call. |
| Purpose | Code reuse and establishing a hierarchical relationship between classes. | Flexibility and the ability to treat objects interchangeably. |
| Relationship | Establishes an "is-a" relationship between classes (subclass is a specific type of superclass). | Achieved through inheritance but not limited to it. Objects can be polymorphic within their own class or ancestor classes. |
| Concept | Compile-time concept. Relationship determined during compilation. | Runtime concept. Actual behavior determined based on the specific object being referenced. |
| Implementation | Involves creating a new class (subclass) that inherits properties and behaviors from a base class (superclass). | Achieved through method overriding and method overloading. |
| Method Overriding | Allows the subclass to provide a different implementation of a method inherited from the superclass. | Essential for achieving polymorphism. Different subclasses can have their own unique implementations of the same method. |
| Method Overloading | Not directly related to inheritance can be used within the same class or hierarchy. | Not directly related to polymorphism, but can be used to provide multiple methods with the same name but different parameters. |
| Use Cases | Modeling real-world hierarchies and code reuse. | Dealing with collections of objects, designing flexible code, and improving modularity and extensibility. |
Remember that while inheritance and polymorphism are distinct concepts, they are closely related and often used together to create powerful and flexible object-oriented systems.
Conclusion
In conclusion, inheritance, and polymorphism are key concepts in object-oriented programming. Inheritance focuses on code reuse and establishing a hierarchical relationship between classes, allowing a subclass to inherit properties and behaviors from a superclass. Polymorphism, on the other hand, emphasizes flexibility and the ability of objects of different classes to respond differently to the same method call. Polymorphism can be achieved through method overriding and method overloading, allowing objects to be treated interchangeably.
By understanding the difference between inheritance and polymorphism, developers can design more modular, extensible, and maintainable code. These concepts provide powerful mechanisms for structuring code and promoting code reuse, while also enabling flexibility and adaptability in handling diverse objects.
FAQs related to the difference between inheritance and Polymorphism
Some FAQs related to the difference between inheritance and polymorphism are discussed below:
Q1. Can you have polymorphism without inheritance?
Yes, polymorphism can be achieved without inheritance. Polymorphism refers to the ability of objects to respond differently to the same method call. While inheritance is commonly used to achieve polymorphism by providing different implementations of methods in subclasses, polymorphism is not limited to inheritance. It can also be achieved through interfaces, abstract classes, or even within a single class using method overloading.
Q2. How does inheritance relate to polymorphism?
Inheritance and polymorphism are closely related. Inheritance establishes a hierarchical relationship between classes, where a subclass inherits properties and behaviors from a superclass. Polymorphism, on the other hand, refers to the ability of objects to take on multiple forms and respond differently to the same method call. Inheritance enables polymorphism by allowing method overriding in subclasses, which allows different subclasses to have their own unique implementations of the same method. Polymorphism allows objects of these different subclasses to be treated interchangeably when working with the superclass.
Q3. Which one is more important, inheritance or polymorphism?
Both inheritance and polymorphism are important concepts in object-oriented programming, but their significance depends on the specific requirements of the system being developed. Inheritance facilitates code reuse and establishes relationships between classes, while polymorphism promotes flexibility and modularity. The choice between them depends on the design goals and the need for code organization, reuse, and adaptability.
Q4. Can you have inheritance without polymorphism?
Yes, it is possible to have inheritance without polymorphism. Inheritance alone does not imply polymorphism. Inheritance is primarily concerned with establishing a hierarchical relationship between classes and facilitating code reuse. Polymorphism, on the other hand, is an additional feature that can be achieved through inheritance, but it is not mandatory. Polymorphism requires method overriding or method overloading to provide different behaviors for objects of different classes.
Q5. Are inheritance and polymorphism limited to object-oriented programming?
Inheritance and polymorphism are concepts that are primarily associated with object-oriented programming (OOP). They are fundamental principles in languages like Java, C++, and Python, which are object-oriented. However, the concept of polymorphism, in a broader sense, can also be found in other paradigms or programming models. For example, functional programming languages may have mechanisms that allow for polymorphic behavior, although they may not employ inheritance as a means of achieving it.