What is the C++ programming language?

C++ is a general-purpose programming language that combines low-level programming features with modern development paradigms. C++ is used in a wide range of fields, from operating systems to game development.

How did C++ come about?

Developer Bjarne Stroustrup set out to create an improved version of the C language. His primary goal was to create a programming language for developing high-performance and scalable applications. Therefore, he added encapsulated classes to the language. This paved the way for the implementation of modern object-oriented programming principles in C++.

As the C++ language evolved and new versions appeared, its differences from C increased. Nevertheless, the developer intentionally maintained C++ compatibility with C: a special translator can convert C++ code into C, and C++’s basic syntax is virtually identical to C’s.

In 1998, the first version of the language (C++98) was standardized, and since then, updates have been released regularly: C++11, C++14, C++17, and C++20. Each new version expanded functionality, improved usability, and performance. For example, C++11 introduced support for lambda expressions, smart pointers, and multithreading. C++17 simplified the syntax and added many new libraries, and C++20 introduced concepts and coroutines.

Thus, C++ is constantly evolving and improving, responding to modern development trends and offering new capabilities. In 2024, TIOBE ranked it among the top three most popular languages, competing with Python and JavaScript.

Key Features of C++

C++ offers a wide range of features that make it a flexible and productive programming language. Let’s list some of them.

Object-oriented programming (OOP)

C++ supports classes, inheritance, polymorphism, and encapsulation. This allows you to organize your code into easily maintainable structures. For example:

#include <iostream>
#include <string>
#include <utility> // Included for std::move

class Car {
private:
    std::string brand;
    int speed;

public:
    // Constructor to initialize the Car object
    Car(std::string carBrand, int carSpeed) 
        : brand(std::move(carBrand)), speed(carSpeed) {}

    // Display function marked as const since it doesn't modify object state
    void display() const {
        std::cout << "Car brand: " << brand << ", Speed: " << speed << " km/h\n";
    }
};

int main() {
    // Create and initialize the car in a single line using the constructor
    Car car1("Toyota", 120);
    car1.display();

    return 0;
}

This code snippet shows how to create a class with fields and methods, how to use an object of the class, and how to print data to the screen using the C++ Standard Library.

Working with memory

In C++, you can manage memory directly using the newand operators delete. This provides great flexibility, but requires care to avoid memory leaks. For example:

#include <iostream>
#include <memory>

int main() {
    std::unique_ptr<int> ptr = std::make_unique<int>(10);
    std::cout << *ptr << std::endl;
} // Memory is automatically freed here when ptr goes out of scope

If you don’t specifically need heap allocation, it is much simpler and faster to store the integer directly on the stack.

#include <iostream>

int main() {
    int val = 10;
    std::cout << val << std::endl;
}

The code demonstrates working with dynamic memory allocation in C++ and pointers.

Templates

Templates allow you to write universal functions and classes that work with any data type. Here’s a simple example of function templates in C++ for working with different data types:

#include <iostream>

template <typename T>
T add(T a, T b) {
    return a + b;
}

int main() {
    std::cout << add(3, 5) << std::endl;         // Output: 8
    std::cout << add(3.5, 2.1) << std::endl;     // Output: 5.6
    return 0;
}

Standard Library (STL)

The STL includes containers (vectors, lists), algorithms (sorting, searching), and iterators, allowing you to quickly develop efficient applications.

For example, this code sorts the elements of the vector of numbers in ascending order and displays them on the screen separated by spaces:

#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    std::vector<int> numbers = {5, 2, 9, 1, 5};
    
    // Sort the vector in ascending order
    std::sort(numbers.begin(), numbers.end());
    
    // Print the sorted elements
    for (int num : numbers) {
        std::cout << num << " ";
    }
    std::cout << std::endl;
    
    return 0;
}

Modern C++ Alternative (C++20)

If you are using C++20 or later, you can simplify the sorting process using ranges:

#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    std::vector<int> numbers = {5, 2, 9, 1, 5};
    
    std::ranges::sort(numbers);
    
    for (int num : numbers) {
        std::cout << num << " ";
    }
    std::cout << '\n';
    
    return 0;
}

What do they write in C++?

C++ remains one of the most popular programming languages, used in a wide range of fields. These include:

• Operating systems. Most of Windows, elements of macOS, and the Linux kernel are written in C++.
• Game engines. Unreal Engine and Unity actively use C++ to create high-performance games.
• Browsers. Major browsers such as Google Chrome and Mozilla Firefox use C++ to process graphics and run their engines.
• Graphic editors. Adobe Photoshop and Illustrator are partially based on C++.
• Scientific applications. MATLAB programs for simulations and scientific calculations.
• Financial systems. Trading platforms and high-frequency trading systems.
• Embedded systems. Programming microcontrollers in cars, IoT devices, and home appliances.

How to program in C++?

To effectively write, test, and debug C++ programs, development environments (IDEs) are used. Here are some popular options:

• Visual Studio is a powerful and popular IDE from Microsoft that provides debugging, syntax highlighting, and a variety of tools for C++ development.
• CLion is a cross-platform IDE from JetBrains with intelligent code completion and CMake support.
• Code::Blocks is a lightweight and customizable IDE suitable for beginners and experienced developers.
• Dev-C++ is a simple and fast environment for creating and compiling C++ programs.
• Xcode is a development environment for macOS, ideal for C++ programming on Apple platforms.
• Eclipse CDT is an extension for the popular Eclipse environment that adds support for C++.

The choice of environment depends on the operating system, project requirements, and the personal preferences of the developer.

How to write a program in C++?

You can create code in C++ by following a few sequential steps. Here’s how to write “Hello, World” in C++.

1. Prepare the development environment for C++

Install a C++ compiler, such as GCC, Clang, or Microsoft Visual C++. Then install an IDE for easy writing and debugging:

• Visual Studio (Windows);
• CLion (cross-platform);
• Code::Blocks;
• Dev-C++.

2. Create a program

Open a text editor or IDE. Write a basic C++ program template, for example:

#include <iostream> // Include the standard input/output stream library

int main() {
    // Output "Hello, World!" to the console, followed by a newline
    std::cout << "Hello, World!" << std::endl;

    // Return 0 to signal that the program executed successfully
    return 0;
}

Save the file with a .cpp extension, for example, program.cpp.

3. Perform compilation

If you’re using an IDE, open the project, add a file, and click Build/Compile. If you’re working in a terminal, navigate to the folder containing your file. Compile the file using a compiler. Example for GCC:

g++ program.cpp -o program

Here, -o program specifies the name of the executable file to be created.

4. Run the program

In the IDE: Click the Run button. In the terminal: ./program. If all steps up to this point have been completed correctly, the program will display:

Hello, World!

5. Debug and test

Ensure the program works correctly for all possible input scenarios. Use the debugger in your IDE to analyze the program’s operation.

This approach can be used to create both simple C++ programs and complex applications like antivirus software. However, creating an antivirus in C++ requires additional knowledge and experience in C++ programming.

Conclusion

C++ is a general-purpose programming language that combines high performance and flexibility for developing applications of varying complexity. It can be used to develop games, embedded systems, and high-load services, making it popular across a wide range of industries. Learn more about C and C++ in our free course.

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