Binary to String in JavaScript

Question

I have created a JavaScript program to convert a string into binary.

Input: StackOverflow
Output: 1010011 1110100 1100001 1100011 1101011 
1001111 1110110 1100101 1110010 1100110 
1101100 1101111 1110111

Now I want to convert that binary back into a string like below. Is there any possible way of doing this?

Input: 1010011 1110100 1100001 1100011 1101011 
1001111 1110110 1100101 1110010 1100110 
1101100 1101111 1110111 

Output StackOverflow

Thanks

You may check the solution over here: [Covert binary to text using javascript](https://stackoverflow.com/questions/21354235/converting-binary-to-text-using-javascript/21354328) — Shivani Sonagara, Jul 03 '19 at 09:29
https://stackoverflow.com/questions/21354235/converting-binary-to-text-using-javascript/21354328 — ellipsis, Jul 03 '19 at 09:30

MauriceNino · Accepted Answer · 2022-03-03T13:07:34.120

Use String.fromCharCode() and parseInt( , 2) like this:

const binary = `1010011 1110100 1100001 1100011 1101011 
1001111 1110110 1100101 1110010 1100110 
1101100 1101111 1110111`;

const outputStr = binary
  // split string into an array of base 2 (binary) UTF-16 chars
  .split(' ')
  // map every binary char to a UTF-16 number of base 10
  // and then get the string representation of that UTF-16 number
  .map(bin => String.fromCharCode(parseInt(bin, 2)))
  // join the array back to a single string
  .join('');

console.log(outputStr);

String.fromCharCode(number) will return a String from a UTF-16 char code
parseInt(binary , 2) will transform a base 2 number string into a base 10 number

Edit:

As the String.fromCharCode() function accepts multiple chars as parameters, you could also use the Spread Operator (...) like so:

const binary = `1010011 1110100 1100001 1100011 1101011 
1001111 1110110 1100101 1110010 1100110 
1101100 1101111 1110111`;

const outputStr = String.fromCharCode(
  ...binary.split(' ').map(bin => parseInt(bin, 2))
)

console.log(outputStr);

Edit 2:

As this answer gets more traffic over time, I am going to also add the solution to do it the other way around too ... just in case:

const str = `StackOverflow`;

const outputStr = str.split('') // split in single chars
  .map(c => c.charCodeAt(0) // get the UTF-16 code (10 base)
             .toString(2)) // transform it back to a string (2 base)
  .join(' ') // make single string from array

console.log(outputStr);

Ok bro got everything but what does the code bin mean which is used in first example — Subha Jeet Sikdar, Jul 03 '19 at 11:10
@SubhaJeetSikdar `bin` is the name of the parameter for the function you pass to map. The function map takes an arrow function with one parameter which you can give any name you like. `bin` could essentially be called `someVariable` too. The variable itself represents one element from the array. The map function iterates over all elements of the array and applies the arrow function (`varName => parseInt(varName , 2)`) on each. — MauriceNino, Jul 03 '19 at 11:13
These are called [Template Literals](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals). Check them out, they are really useful in JavaScript. @SubhaJeetSikdar — MauriceNino, Jul 04 '19 at 08:35
NB: if you put Unicode characters through this you'll see binary numbers of up to 16 bits in length. — Alnitak, Oct 14 '20 at 11:19

Abregre · Answer 2 · 2020-10-15T14:57:25.177

str ="01000001 01110010 01100101 01101110 00100111 01110100 00100000 01100010 01101111 01101110 01100110 01101001 01110010 01100101 01110011 00100000 01100110 01110101 01101110 00100001 00111111"
    
    
function binaryAgent(str) {
      return str.split(' ').map(letter=>String.fromCharCode(parseInt(letter, 2))).join('')
     
}
    
console.log(binaryAgent(str))

First we use the .split() method to convert the string to array using the ' '(space character)
After that we use the .map() high-order loop method to iterate through each binary-code-letter
For each binary-code-letter we use String.fromCharCode() on parseInt('each letter',2)=> which converts the binary string to a number. The second argument "2" of the parseInt method which is called(radix) is to define which numeral system we want to use.
Finally we can join the manipulated array back together calling the join('') method but this time we don't use a space between

=======

Please add some explanation for your answer so that audience can understand the working of the code — Not A Bot, Oct 14 '20 at 13:26
and also explain how it improves on the accepted answer (hint: it doesn't, because apart from wrapping into a function the code is identical apart from the variable names). — Alnitak, Oct 14 '20 at 13:40

score 1 · Answer 3 · answered Oct 14 '20 at 11:11

1

const binary = `1010011 1110100 1100001 1100011 1101011 
1001111 1110110 1100101 1110010 1100110 
1101100 1101111 1110111`;

const inputStr = binary.split(' ');
const output = [];
inputStr.forEach(item => {output.push(String.fromCharCode(parseInt(item, 2)))});
console.log(output.join(''));

answered Oct 14 '20 at 11:11

Godsonaddy

27
3

1

downvote for using `forEach()` with a `push` instead of `.map` . You've copied the accepted answer, and made it _worse_. – Alnitak Oct 14 '20 at 11:19
@Alnitak just an alternative. Makes sense to use map tho – Godsonaddy Oct 14 '20 at 11:21
3

using foreach/push instead of map is an _anti-pattern_. There is no good reason for it, and it would be a down-mark in any code review. – Alnitak Oct 14 '20 at 11:32

Binary to String in JavaScript

3 Answers3

Edit:

Edit 2:

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