Classes-and-objects-in-cpp

C++ Basic Programs – Class and Object Concepts

Aim

To implement and understand the basic concepts of C++ such as classes, objects, access specifiers, member functions, arrays, and simple arithmetic operations through a set of beginner-friendly programs.

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Theory

C++ is a powerful, object-oriented programming language that provides features for building efficient and organized software. One of the key strengths of C++ is its support for classes and objects, which help model real-world entities and enable modular, reusable, and maintainable code.

This project focuses on the following core C++ concepts:

1. Classes and Objects

• A class is a user-defined data type that contains variables (data members) and functions (member functions).
• An object is an instance of a class, used to access and manipulate the data inside it.
• This promotes modularity, data abstraction, and reusability.

2. Access Specifiers

• C++ uses public, private, and protected keywords to control access to class members.
  • Public members are accessible from anywhere in the program.
  • Private members can only be accessed within the class.
• This ensures encapsulation, protecting the internal state of an object from unintended interference.

3. Member Functions (Inside and Outside Class)

• Member functions can be written inside the class (inline) or defined outside using the scope resolution operator (::).
• Writing functions outside the class helps separate interface from implementation, making the code cleaner and more maintainable.

4. Arrays and Looping

• Arrays store multiple values of the same type.
• Looping (using for, while) is used to iterate through arrays, reverse elements, or perform operations on collections of data.
• Functions are used alongside arrays to improve code structure and reusability.

5. Arithmetic and Geometric Calculations

• Programs like Cube Volume, Cuboid Volume, and Rectangle Area demonstrate how simple mathematical formulas are implemented using class attributes and functions.
• These are useful in developing logic for real-world problem-solving using code.

6. Real-Life Abstraction

• Classes like Car and Student show how real-world objects can be represented in code using attributes and behaviors.
• This is the foundation of object-oriented programming (OOP) and prepares learners for building complex systems later.

These programs help learners get hands-on experience with the syntax, structure, and logic of C++, building a solid foundation for more advanced topics.

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Algorithms

1. Car Details.cpp

   • Create a class with car attributes like brand, model, and year.
   • Input and display details using class functions.

2. Cube Volume (Inside Class).cpp

   • Define a cube class with side length.
   • Calculate volume inside the class using: volume = side³.

3. Cube Volume (Outside Class).cpp

   • Same as above, but define volume calculation outside the class.

4. Cuboid Volume Inside Class.cpp

   • Class with length, width, height.
   • Calculate volume inside the class: volume = l × w × h.

5. Outside Class.cpp

   • Demonstrates how to define class methods outside the class using ::.

6. Rectangle Area.cpp

   • Class with length and breadth.
   • Calculate area: area = length × breadth.

7. Reverse Array Outside Class.cpp

   • Take input of array elements.
   • Reverse and print the array using a separate function.

8. Simple Calculator.cpp

   • Perform basic arithmetic operations (+, -, *, /) using conditional logic.

9. Student Details.cpp

   • Class with student name, roll, and marks.
   • Input and display using class methods.

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Conclusion

These programs provide a practical understanding of C++ fundamentals such as class creation, encapsulation, function definitions, and array manipulation. They serve as a stepping stone for beginners to build confidence and prepare for more advanced topics in C++, including inheritance, polymorphism, file handling, and data structures. This project helps develop structured thinking and object-oriented problem-solving skills.

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