1. What is C++?

C++ is a powerful, general-purpose programming language developed by Bjarne Stroustrup. It is widely used for system software, games, applications, and competitive programming.

2. Features of C++

• Fast and efficient
• Object-Oriented Programming (OOP)
• Supports low-level memory manipulation
• Portable and widely supported

3. Basic Structure of a C++ Program

#include <iostream>
using namespace std;

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

4. Variables and Data Types

Variables store data values.

int age = 18;
float height = 5.9;
char grade = 'A';
bool isStudent = true;
    

• int – integer numbers
• float – decimal numbers
• char – single character
• bool – true or false

5. Input and Output

#include <iostream>
using namespace std;

int main() {
    int number;
    cout << "Enter a number: ";
    cin >> number;
    cout << "You entered: " << number;
    return 0;
}
    

6. Conditional Statements

C++ uses conditions to make decisions.

int age = 20;

if (age >= 18) {
    cout << "Eligible to vote";
} else {
    cout << "Not eligible to vote";
}
    

7. Loops

Loops repeat a block of code.

// for loop
for(int i = 1; i <= 5; i++) {
    cout << i << " ";
}
    

// while loop
int i = 1;
while(i <= 5) {
    cout << i << " ";
    i++;
}
    

8. Functions

Functions are reusable blocks of code.

int add(int a, int b) {
    return a + b;
}
    

9. Arrays

int marks[5] = {80, 85, 90, 75, 88};

for(int i = 0; i < 5; i++) {
    cout << marks[i] << " ";
}
    

10. Object-Oriented Programming (OOP)

C++ supports OOP concepts:

• Class
• Object
• Inheritance
• Polymorphism
• Encapsulation

class Student {
public:
    string name;
    int age;

    void display() {
        cout << name << " " << age;
    }
};
    

11. Applications of C++

• Game development
• Operating systems
• Embedded systems
• Competitive programming