Inheritance vs. Polymorphism: What's the Difference?
Edited by Aimie Carlson || By Janet White || Published on July 9, 2024
Inheritance is a mechanism where a new class derives properties and behaviors from an existing class, while polymorphism allows objects of different classes to be treated as objects of a common super class.
Key Differences
Inheritance is a fundamental concept in object-oriented programming (OOP) where a new class (subclass) extends an existing class (superclass), inheriting its attributes and methods. Polymorphism, on the other hand, is the ability of objects from different classes to respond to the same method calls in different, class-specific ways. Both concepts are pillars of OOP, promoting code reusability and flexibility.
Inheritance establishes a relationship between two classes as parent and child, enabling the child to inherit traits from the parent, while polymorphism focuses on the ability of different objects to respond uniquely to the same interface or method call. Inheritance creates a hierarchical relationship, whereas polymorphism uses those relationships to enable multiple forms of behavior.
Inheritance is used to express an "is-a" relationship between classes, meaning the subclass is a specific type of the superclass. Polymorphism, however, uses an "has-a" or "can-do" relationship, where different classes can implement the same interface or method differently. While inheritance is about extending functionality, polymorphism is about utilizing it in varied ways.
Inheritance involves creating new classes based on existing ones, simplifying code and avoiding redundancy. Polymorphism, especially in its subtype form, allows for dynamic method binding, where the method that gets executed depends on the object's class, even though it's called through a reference of a superclass. This dynamic behavior is a cornerstone of polymorphism.
A key difference lies in their implementation: inheritance is implemented through extending classes, while polymorphism is implemented through interfaces and abstract classes, enabling objects to be treated as instances of their superclass. Inheritance provides a clear structure, while polymorphism offers flexibility in executing methods.
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Comparison Chart
Definition
Extending a class from another class.
Objects of different classes treated similarly.
Relationship
"Is-a" relationship between classes.
"Can-do" ability across different classes.
Implementation Mechanism
Through extending classes.
Through interfaces and abstract classes.
Code Reusability
Promotes reusability by inheriting properties.
Enables diverse behaviors with common interface.
Flexibility
Establishes a clear hierarchical structure.
Offers dynamic method execution.
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Inheritance and Polymorphism Definitions
Inheritance
Deriving a new class from an existing class.
In Java, the class Dog extends the class Animal, showing inheritance.
Polymorphism
Multiple meanings of words or phrases.
The word bank exhibits linguistic polymorphism with its different meanings.
Inheritance
Receiving assets from a deceased relative.
She received a large inheritance from her grandfather.
Polymorphism
Occurrence of different forms or types in organisms.
The polymorphism in butterflies results in various wing patterns.
Inheritance
Passing down of cultural values and traditions.
The festival is part of their cultural inheritance.
Polymorphism
Existence of a substance in more than one form.
Carbon shows polymorphism, existing as diamond and graphite.
Inheritance
Legacy or heritage from historical contexts.
The ancient ruins are a part of the city's historical inheritance.
Polymorphism
Diversity of cultural expressions.
The festival shows cultural polymorphism with its varied traditions.
Inheritance
Genetic transmission of traits from parents to offspring.
His eye color is a direct inheritance from his mother.
Polymorphism
Different classes responding to the same interface.
In OOP, polymorphism allows different object types to use a common method.
Inheritance
The action of inheriting something
The inheritance of property from a relative.
Polymorphism
(Biology) The occurrence of more than one form, as several alleles of a particular gene or winged and wingless forms of the same species.
FAQs
What is inheritance in OOP?
It's a mechanism where a class inherits properties and methods from another class.
Can inheritance be multiple in some languages?
Yes, languages like C++ support multiple inheritance, but others like Java do not.
What is polymorphism in programming?
It allows objects of different types to be treated as objects of a common super type.
Can inheritance lead to issues?
Yes, improper use can lead to complex and fragile code structures.
How does cultural inheritance affect society?
It passes down values and traditions, shaping social norms and identity.
Can inheritance be skipped in OOP?
It can be, but it's a fundamental concept for designing object-oriented systems.
Is biological polymorphism significant in evolution?
Yes, it contributes to genetic diversity and adaptability.
Is polymorphism only about methods?
Mostly, but it can also involve polymorphic properties in some languages.
How does inheritance promote code reusability?
By allowing new classes to use properties and methods of existing classes.
Is polymorphism related to inheritance?
Yes, it often works with inheritance but can also be independent.
Can inheritance be overridden?
In OOP, subclasses can override inherited methods.
Can inheritance be partial?
In some languages, selective inheritance is possible using interfaces.
What is the role of polymorphism in ecosystems?
Biological polymorphism increases biodiversity and ecological resilience.
How does polymorphism enhance flexibility?
By allowing different classes to implement the same methods in different ways.
How does linguistic polymorphism enrich language?
By allowing words to have multiple meanings, adding depth and complexity.
Is polymorphism a design pattern?
No, but it's used in many design patterns for flexible and reusable code.
Does inheritance always involve genetics?
In biological contexts, yes, but the term is broader in other fields.
How do interfaces relate to polymorphism?
They define methods that different classes can implement in their own way.
Is cultural inheritance always positive?
Not always, as it can perpetuate negative or outdated values and practices.
Does legal inheritance always involve wills?
Not necessarily, as laws of intestacy apply if there's no will.
About Author
Written by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
Edited by
Aimie CarlsonAimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.
