1.3) Hello World program in C++

Let’s break down the “Hello World” program in C++ step by step, including code examples with explanations and the output of the code.

Step 1: Include the Necessary Header File

In C++, you need to include the necessary header file to access standard input and output functions.

#include <iostream>

This line includes the <iostream> header, which provides functions like cout (for output) and cin (for input).

Step 2: Define the main() Function

The main() function is the entry point of a C++ program. It’s where the program execution begins.

int main() {
    // Code goes here
    return 0;
}

The int before main() indicates that the function returns an integer value. The return 0; statement signals the successful termination of the program.

Step 3: Output “Hello, World!”

To display “Hello, World!” on the console, use the std::cout (character output) stream.

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

In the above code:

• std::cout is the standard output stream.
• << is the stream insertion operator, used to insert data into the stream.
• "Hello, World!" is the text you want to output.
• << std::endl inserts a newline and flushes the output buffer.

Full Code

Here’s the complete “Hello World” program in C++:

#include <iostream>

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

Output:

Hello, World!

Explanation:

• The #include <iostream> line includes the necessary header.
• The main() function is the entry point of the program.
• std::cout << "Hello, World!" << std::endl; outputs “Hello, World!” to the console.
• return 0; indicates successful program execution.

This simple program demonstrates the basic structure of a C++ program and how to use the std::cout stream to output text to the console.