Learning C++ basics by wyurtrft. aka листик.

# Introduction to C++

Welcome to the exciting world of C++! In this introduction, we'll explore the fundamental concepts of this powerful programming language and set the stage for your learning journey.

## What is C++?

C++ is a general-purpose programming language that was developed by Bjarne Stroustrup at Bell Labs in the early 1980s. It is an extension of the C programming language and is widely used for system programming, application development, game development, and many other domains.

## Why Learn C++?

C++ offers several advantages that make it a valuable language to learn:

1.  **Performance**: C++ is known for its high performance and efficient memory management, making it suitable for developing system software, games, and applications that require low-level control and optimization.

2.  **Object-Oriented Programming (OOP)**: C++ fully supports object-oriented programming concepts, such as classes, inheritance, polymorphism, and encapsulation, enabling developers to create modular, reusable, and maintainable code.

3.  **Portability**: C++ programs can be compiled and run on various platforms, including Windows, Linux, and macOS, making it a cross-platform language.

4.  **Versatility**: C++ can be used for a wide range of applications, from operating systems and device drivers to video games and scientific simulations.

5.  **Industry Demand**: C++ is widely used in various industries, including finance, gaming, embedded systems, and more, making it a valuable skill for programmers.

## What's Next?

In the upcoming chapters, we'll dive into the fundamentals of C++, including data types, variables, operators, control structures, functions, classes, and more. We'll also explore advanced topics like templates, exceptions, and the Standard Template Library (STL).

To help you understand the concepts better, we'll provide code examples and practical exercises, allowing you to put your knowledge into practice.

So, let's embark on this exciting journey and unlock the power of C++!


Chapter 0: Intro

Introduction

```cpp
// A simple "Hello, World!" program in C++
#include <iostream>

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

Let's break down this code line by line:

`#include <iostream>`: This line includes the iostream header file, which contains definitions for objects like std::cout (standard output) and std::endl (end line character).

`int main() {`: The main() function is the entry point for most C++ programs. It returns an integer value (in this case, 0) upon successful completion.

`std::cout << "Hello, World!" << std::endl;` : This line prints the string "Hello, World!" to the standard output stream (usually the terminal or console), and then adds a newline character std::endl.

`return 0;`: This line returns the value 0, indicating successful program termination.

When you compile and run this program, it will simply print `Hello, World!` in the terminal or console.


Chapter 1 : Basics

Hello World

# Comments in C++

In programming, comments are essential for documenting code and improving its readability. Comments are ignored by the compiler and serve as explanations or notes for developers. C++ provides two types of comments: single-line comments and multi-line comments.

## Single-Line Comments

Single-line comments are used to explain a particular line or a small section of code. They start with two forward slashes (`//`) and continue until the end of the line.

```cpp
// This is a single-line comment
int x = 10; // This line assigns the value 10 to the variable x
```

```cpp
/*
 * This is a multi-line comment
 * It can span multiple lines
 * and provide detailed explanations
 */
```

```cpp
/* This program demonstrates the use of comments in C++ */

#include <iostream>

int main() {
    // Declare and initialize a variable
    int x = 10;

    /*
     * This block of code prints the value of x
     * and then increments it by 1
     */
    std::cout << "The value of x is: " << x << std::endl;
    x++; // Increment x by 1

    // Print the updated value of x
    std::cout << "The new value of x is: " << x << std::endl;

    return 0;
}
```
