Introduction to C++

Here are some C++ code snippets that illustrate some of the most important concepts in C++. This introduction will cover basic syntax, data types, control structures, object-oriented programming, and more.

1. Basic Syntax and Output

#include <iostream>

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

This simple program prints “Hello, World!” to the console. It introduces the inclusion of headers (#include <iostream>), the main function, basic output (std::cout), and the return statement.

2. Variables and Data Types

#include <iostream>

int main() {
    int age = 30;
    double salary = 45000.50;
    char grade = 'A';
    bool isEmployed = true;

    std::cout << "Age: " << age << ", Salary: " << salary;
    std::cout << ", Grade: " << grade << ", Employed: " << isEmployed << std::endl;

    return 0;
}

This snippet demonstrates declaring and initializing variables of different data types like int, double, char, and bool.

3. Control Structures (if-else)

#include <iostream>

int main() {
    int score = 85;

    if (score >= 90) {
        std::cout << "Grade A" << std::endl;
    } else if (score >= 80) {
        std::cout << "Grade B" << std::endl;
    } else {
        std::cout << "Grade C" << std::endl;
    }

    return 0;
}

Here, we use if, else if, and else statements to make decisions based on the value of score.

4. Loops (for and while)

#include <iostream>

int main() {
    // for loop
    for (int i = 0; i < 5; i++) {
        std::cout << "i = " << i << std::endl;
    }

    // while loop
    int j = 0;
    while (j < 5) {
        std::cout << "j = " << j << std::endl;
        j++;
    }

    return 0;
}

This code shows how to use for and while loops for iterating over a range of numbers.

5. Functions

#include <iostream>

int add(int x, int y) {
    return x + y;
}

int main() {
    int result = add(5, 3);
    std::cout << "5 + 3 = " << result << std::endl;
    return 0;
}

This demonstrates defining and calling a simple function that adds two numbers.

6. Classes and Object-Oriented Programming

#include <iostream>

class Car {
public:
    std::string color;
    int year;

    void drive() {
        std::cout << "Driving a " << color << " car from " << year << std::endl;
    }
};

int main() {
    Car myCar;
    myCar.color = "red";
    myCar.year = 2020;
    myCar.drive();

    return 0;
}

This snippet introduces a basic class with attributes and a method, showcasing the fundamental aspects of object-oriented programming in C++.

These snippets provide a quick tour through the essential elements of C++ programming and serve as a foundation for further exploration into more advanced topics in the language.