A C++ program's execution begins with a function named main. This function serves as the entry point for the application.

int main()
{
    // Program logic is placed here.
}

The keyword int specifies the function's return type. A function consists of four primary components: the return type, the function name, a parameter list enclosed in parentheses, and the function body enclosed in braces {}.

While main is not a reserved keyword in the language, the compiler and runtime environment require its presence for a program to be executable.

An empty parameter list, as shown above, indicates the function accepts no arguments. Functions can also be defined to receive parameters.

int main(int firstValue, int secondValue)
{
    // Code that uses firstValue and secondValue.
}

Comments, which are ignored by the compiler, can be added using double slashes //.

Classes are user-defined types that allow for data abstraction. Their definitions are typically separated into a header file, which declares the class interface, and a source file containing the implementation.

To perform input and output operations, the standard iostream library is used. Its functionality must be made available by including the appropriate header.

#include <iostream>

The predefined cout object, coupled with the output operator <<, is used to write data to the standard output stream.

std::cout << "Enter your name: ";

This line is a sattement, the fundamental unit of execution in C++, terminated by a semicolon.

To store user input, an object of a suitable type must be declared. For textual data, the standard string class is appropriate.

std::string userName;

This is a declaration statement. To use the string class, its header must also be included.

#include <string>

User input is read from the standard input stream cin using the input operator >>.

std::cin >> userName;

To move the output cursor to a new line, the newline character constant '\n' can be sent to cout. Character literals are ecnlosed in single quotes.

std::cout << '\n';