What is the difference between class and structure in C?

Table of Contents

• Introduction
• Differences Between Class and Structure in C
  • Language Support
  • Data Encapsulation
  • Member Functions
  • Inheritance and Polymorphism
• Practical Examples
  • Example 1: Defining and Using a Structure in C
  • Example 2: Comparing with a Class (Conceptual)
• Conclusion

Introduction

In C programming, the concept of classes does not exist as it does in object-oriented languages like C++. However, understanding the difference between structures in C and classes in other languages can provide insight into how data is organized and managed in C. This guide explores the differences between structures in C and classes in object-oriented programming languages.

Differences Between Class and Structure in C

Language Support

• Class: Classes are not a feature of the C language. C is a procedural programming language and does not support classes or object-oriented programming concepts directly.

• Structure: In C, structures (struct) are used to group related data items. Structures are a fundamental feature of C and are used to define custom data types that group variables of different types together.

  Example:

Data Encapsulation

• Class: In languages that support classes (like C++ or Java), classes encapsulate data and functions into a single unit. Classes can have private, protected, and public members, allowing for control over data access and modification.

• Structure: In C, structures do not support data encapsulation. All members of a structure are public and can be accessed directly. There is no built-in mechanism for restricting access to the structure's members.

  Example:

Member Functions

• Class: Classes in object-oriented languages can have member functions (methods) that operate on the class's data. This allows for encapsulation and object-oriented design.

• Structure: In C, structures cannot have member functions. They are purely data containers, and any functions that operate on structures must be defined separately.

  Example:

Inheritance and Polymorphism

• Class: In object-oriented languages, classes support inheritance and polymorphism. Classes can inherit from other classes and override methods to provide different implementations.
• Structure: C structures do not support inheritance or polymorphism. They are limited to simple data grouping without object-oriented features.

Practical Examples

Example 1: Defining and Using a Structure in C

Example 2: Comparing with a Class (Conceptual)

In C++, a similar concept using a class would be:

Conclusion

In C, structures are used to group related data but lack the features of classes found in object-oriented programming languages. Structures in C are simple data containers without encapsulation or member functions, and they do not support inheritance or polymorphism. Understanding these differences highlights the limitations of C in comparison to languages with full object-oriented capabilities.