Decode a Binary Message using JavaScript

#javascript #tutorial

Today I passed 14k subs on Twitter and as usual I wrote a tweet to thank all the people who support me on this journey.

But this time I did something different. Instead of staying: 14,000, I've put the number in binary: 11011010110000.

And something fun happened...

My good friend Mike replied with a message that was in binary format. 🙈

Mike Eling

@drfr0st

@florinpop1705 01010100 01101000 01100001 01110100 00100111 01110011 00100000 01110011 01101111 00100000 01100011 01101111 01101111 01101100 00100000 01000110 01101100 01101111 01110010 01101001 01101110 00100001 😊

09:01 AM - 29 Jan 2020

0 1

That's something he would obviously do (because he's a hacker 😆).

So now... I had to decode it.

Here is a Video Tutorial if you are interested to see how I did it:

...

Or for you "lazier" people out there, here is the code:

// storing the message
const mes =
    '01011001 01101111 01110101 00100000 01100001 01110010 01100101 00100000 01110111 01100101 01101100 01100011 01101111 01101101 01100101';

const res = mes
    // split the string into an array of strings (removing the ' ')
    .split(' ')
    // map over the substrings and convert them to numbers
    .map(b => parseInt(b, 2))
    // map over again to convert the numbers to characters
    .map(num => String.fromCharCode(num))
    // join the characters back into a string
    .join('');

// getting the answer
console.log(res);

I hope you enjoyed this little tutorial!

Happy Coding! 😇

Top comments (7)

Aleksandr Hovhannisyan • Jan 29 '20

For anyone wondering, you can also decode this by hand, albeit more slowly:

01010100 01101000 01100001 01110100 00100111 01110011 00100000 01110011 01101111 00100000 01100011 01101111 01101111 01101100 00100000 01000110 01101100 01101111 01110010 01101001 01101110 00100001

Each group of 8 bits is a byte (hence the intentional spacing to make it more obvious—he could've been more cheeky by grouping them all together). And characters on most modern OSes are represented using bytes (1 char = 1 byte).

01010100 = 4 + 16 + 64 = 84 = T in ASCII.

And so on.

Florin Pop • Jan 29 '20

Or that, yes 👍

Barzi • Jan 30 '20

Hi Florin, thank you for your post. I really appreciate the way you wrote your code (I'm one of those lazy guys that didn't watch your video), I find it very clean and straightforward. Keep it up!