What is the difference between inheritance and polymorphism in C?

Table of Contents

• Introduction
• Inheritance vs. Polymorphism in C
  • What is Inheritance in C?
  • What is Polymorphism in C?
• Key Differences
  • Purpose
  • Mechanism
  • Usage
  • Implementation
• Conclusion

Introduction

In C, the concepts of inheritance and polymorphism are not natively supported as they are in object-oriented languages like C++. However, you can simulate these concepts using structures and function pointers. Understanding how to achieve these functionalities in C and the differences between them is important for effective procedural programming and creating flexible, reusable code.

This guide outlines the distinctions between inheritance and polymorphism in C, including how to simulate these concepts and their respective roles.

Inheritance vs. Polymorphism in C

What is Inheritance in C?

In C, inheritance is not directly supported, but you can simulate it using structures (structs). By embedding one struct within another, you can create a hierarchical relationship where a derived struct includes the members of a base struct. This approach allows for code reuse and hierarchical data representation.

Simulating Inheritance with Structs:

Output:

What is Polymorphism in C?

Polymorphism in C is simulated using function pointers within structs. By defining function pointers in a struct, you can achieve a form of dynamic method binding, where different implementations of functions can be called based on the actual type of the object at runtime.

Simulating Polymorphism with Function Pointers:

Output:

Key Differences

Purpose

• Inheritance: In C, inheritance-like behavior is achieved by embedding one struct inside another. This allows for a hierarchical structure where the derived struct inherits attributes from the base struct.
• Polymorphism: In C, polymorphism is simulated using function pointers. This allows different functions to be called through a common interface, enabling dynamic method binding.

Mechanism

• Inheritance: Implemented using structs where one struct contains another struct. This simulates the base and derived class relationship.
• Polymorphism: Implemented using function pointers within structs. This allows the same function call to invoke different implementations based on the type of the object.

Usage

• Inheritance: Used to create hierarchical relationships and reuse code by embedding structs. It models "is-a" relationships, where the derived struct "is-a" type of the base struct.
• Polymorphism: Used to achieve dynamic method binding and treat different types of objects through a common interface. It models "can-do" relationships, where different objects can perform the same operation differently.

Implementation

• Inheritance: Achieved by including one struct as a member of another, and accessing inherited members through the base struct.
• Polymorphism: Achieved by defining function pointers in structs and using them to call different functions based on the actual object type.

Conclusion

In C, inheritance and polymorphism are simulated rather than directly supported. Inheritance-like behavior is achieved through struct embedding, allowing hierarchical relationships and code reuse. Polymorphism is simulated using function pointers, enabling dynamic method binding and flexible object handling. Understanding these simulations helps in designing modular and adaptable code in a procedural programming environment.