A word of warning: This article is not for the faint of heart, nor for those who believe “Hello, World!” should ever be simple.

You might wonder, “Why start with ‘Hello, World!’?” As this is my very first blog post, I wanted to pay homage to the time-honored tradition of beginning every programming journey with this iconic phrase. “Hello, World!” is simple, universal, and instantly recognizable. This makes it the perfect canvas for a little creative overengineering.

#include <iostream>
using namespace std;

int main(int argc, char *argv[]) {
	cout << "Hello, World!\n";  // about time we make it a little interesting
	cout << "\110\145\154\154\157\54\40\127\157\162\154\144\41\12";
	cout << "\x48\x65\x6C\x6C\x6F\x2C\x20\x57\x6F\x72\x6C\x64\x21\xA";
	return 0;
}

In the above snippet, all three cout statements will print the same output: Hello, World! (with a newline for good measure).

To understand how this works, we look to escape sequences. These are special codes that allow you to represent characters that would otherwise be tricky, or impossible, to include directly in a string. For example, if you want to embed a double quotation mark (") inside a string literal, you cannot simply insert it. You must precede it with a backslash (\). There are also classic escape sequences predefined by the language, such as \n for a newline or \t for a tab.

But there’s more. Escape sequences aren’t limited to just the usual suspects. You can also use octal and hexadecimal escape sequences to represent characters by their numeric values. Below are some “obscure” forms:

• \ followed by one, two or three octal digits
• \x followed by one or more hexadecimal digits

The numbers following \ and \x represent the character’s value. For simplicity, let’s assume we are using ASCII character encoding. In plain English, every character in the language maps to a predefined numeric value according to the ASCII specification. The second and third cout statements above use these values in octal and hexadecimal format, respectively, to produce the same familiar message.

A few notes:

• If there are more than three octal digits after \, only the first three are interpreted as part of the escape sequence. The rest are treated as regular characters.
• Hexadecimal digits are not case-sensitive; \x6C is the same as \x6c.

The table below breaks down each character in "Hello, World!\n". You can generalize this approach to any string, should you wish to thoroughly confuse your future self or your colleagues.

I hope you enjoyed this quick dive into the unnecessarily complex world of escape sequences. Remember that just because you can overengineer “Hello, World!” doesn’t mean you should. It sure is fun, though.