Inheritance vs. Polymorphism: What\'s the Key Difference in Object-Oriented Programming?

Understanding the Primary Difference: Inheritance vs. Polymorphism

"What is the main difference between Inheritance and Polymorphism?" is a frequently encountered query, particularly for those commencing their programming journey. Inheritance and polymorphism, while conceptually similar, serve distinct purposes in object-oriented programming.

Inheritance

Inheritance establishes a relationship between a subclass and a superclass. A subclass, such as Student, inherits all attributes and methods from its superclass, like Person. This allows subclasses to inherit the base functionality of their parent classes and extend or modify those characteristics to suit their specific needs. For instance, in the Person-Student example, Student inherits the read method from Person but may override it to implement a different reading experience tailored to student usage.

Polymorphism

Polymorphism is the ability for objects of different subclass types to be treated as objects of their superclass type. This enables the runtime to determine the appropriate method implementation based on the actual object's type at execution time. Consider the example provided earlier:

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

In this scenario, polymorphism dictates that despite assigning a Student object (of the Student class) to the Person reference (of the Person class), the read method of the Student class is invoked. This occurs because a Student is also a Person, and the runtime can differentiate between the two dynamically.

Key Difference

The fundamental difference lies in the purpose of inheritance and polymorphism. Inheritance establishes a hierarchical relationship where objects can be derived from other objects, inheriting their traits. Polymorphism, on the other hand, allows objects of different subclasses to be handled as instances of their superclass, facilitating the invocation of subclass-specific methods during execution.

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