C++ chapter 1

🟩 Chapter 1: Introduction to C++

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🔹 1. What is C++?

• C++ is an object-oriented programming language (OOP) developed by Bjarne Stroustrup in 1979 at Bell Labs.
• It is an extension of C, adding classes and objects.
• Known as a middle-level language (supports both high-level and low-level programming).

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🔹 2. Features of C++

1. Object-Oriented (uses classes & objects)
2. Simple and Fast (based on C)
3. Portable (runs on any platform)
4. Compiled Language (requires compiler)
5. Reusability through functions and classes
6. Rich Library of built-in functions
7. Extensible – new features can be added easily

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🔹 3. Structure of a C++ Program

#include <iostream>
using namespace std;

int main() {
    cout << "Hello, World!";
    return 0;
}

Explanation:

• #include <iostream> → input/output header file
• using namespace std; → allows use of standard C++ features
• main() → starting point of the program
• cout → prints output
• return 0; → ends the program successfully

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🔹 4. Difference Between C and C++

Feature	C	C++
Programming Style	Procedural	Object-Oriented
Data	Functions act on data	Data & functions tied as objects
Security	Less secure	More secure (Encapsulation)
Reusability	Limited	High (via classes)
Inheritance	Not supported	Supported

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🔹 5. OOP Concepts

• Class – Blueprint of objects
• Object – Instance of class
• Encapsulation – Wrapping data & functions together
• Abstraction – Hiding internal details
• Inheritance – Acquiring properties of another class
• Polymorphism – Many forms (e.g., function overloading)

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