[javascript] How to convert text to binary code in JavaScript?

Text to Binary Code

I want JavaScript to translate text in a textarea into binary code.

For example, if a user types in "TEST" into the textarea, the value "01010100 01000101 01010011 01010100" should be returned.

I would like to avoid using a switch statement to assign each character a binary code value (e.g. case "T": return "01010100) or any other similar technique.

Here's a JSFiddle to show what I mean. Is this possible in native JavaScript?

Provided you're working in node or a browser with BigInt support, this version cuts costs by saving the expensive string construction for the very end:

const zero = 0n
const shift = 8n

function asciiToBinary (str) {
  const len = str.length
  let n = zero
  for (let i = 0; i < len; i++) {
    n = (n << shift) + BigInt(str.charCodeAt(i))
  }
  return n.toString(2).padStart(len * 8, 0)
}

It's about twice as fast as the other solutions mentioned here including this simple es6+ implementation:

const toBinary = s => [...s]
  .map(x => x
    .codePointAt()
    .toString(2)
    .padStart(8,0)
  )
  .join('')

If you need to handle unicode characters, here's this guy:

const zero = 0n
const shift = 8n
const bigShift = 16n
const byte = 255n

function unicodeToBinary (str) {
  const len = str.length
  let n = zero
  for (let i = 0; i < len; i++) {
    const bits = BigInt(str.codePointAt(i))
    n = (n << (bits > byte ? bigShift : shift)) + bits
  }
  const bin = n.toString(2)
  return bin.padStart(8 * Math.ceil(bin.length / 8), 0)
}

The other answers will work for most cases. But it's worth noting that charCodeAt() and related don't work with UTF-8 strings (that is, they throw errors if there are any characters outside the standard ASCII range). Here's a workaround.

// UTF-8 to binary
var utf8ToBin = function( s ){
    s = unescape( encodeURIComponent( s ) );
    var chr, i = 0, l = s.length, out = '';
    for( ; i < l; i ++ ){
        chr = s.charCodeAt( i ).toString( 2 );
        while( chr.length % 8 != 0 ){ chr = '0' + chr; }
        out += chr;
    }
    return out;
};

// Binary to UTF-8
var binToUtf8 = function( s ){
    var i = 0, l = s.length, chr, out = '';
    for( ; i < l; i += 8 ){
        chr = parseInt( s.substr( i, 8 ), 2 ).toString( 16 );
        out += '%' + ( ( chr.length % 2 == 0 ) ? chr : '0' + chr );
    }
    return decodeURIComponent( out );
};

The escape/unescape() functions are deprecated. If you need polyfills for them, you can check out the more comprehensive UTF-8 encoding example found here: http://jsfiddle.net/47zwb41o

Thank you Majid Laissi for your answer

I made 2 functions out from your code:

the goal was to implement convertation of string to VARBINARY, BINARY and back

const stringToBinary = function(string, maxBytes) {
  //for BINARY maxBytes = 255
  //for VARBINARY maxBytes = 65535
  let binaryOutput = '';
  if (string.length > maxBytes) {
    string = string.substring(0, maxBytes);
  }

  for (var i = 0; i < string.length; i++) {
    binaryOutput += string[i].charCodeAt(0).toString(2) + ' ';
  }

  return binaryOutput;
};

and backward convertation:

const binaryToString = function(binary) {
  const arrayOfBytes = binary.split(' ');

  let stringOutput = '';

  for (let i = 0; i < arrayOfBytes.length; i++) {
    stringOutput += String.fromCharCode(parseInt(arrayOfBytes[i], 2));
  }

  return stringOutput;
};

and here is a working example: https://jsbin.com/futalidenu/edit?js,console

this seems to be the simplified version

Array.from('abc').map((each)=>each.charCodeAt(0).toString(2)).join(" ")

Here's a pretty generic, native implementation, that I wrote some time ago,

// ABC - a generic, native JS (A)scii(B)inary(C)onverter.
// (c) 2013 Stephan Schmitz <[email protected]>
// License: MIT, http://eyecatchup.mit-license.org
// URL: https://gist.github.com/eyecatchup/6742657
var ABC = {
  toAscii: function(bin) {
    return bin.replace(/\s*[01]{8}\s*/g, function(bin) {
      return String.fromCharCode(parseInt(bin, 2))
    })
  },
  toBinary: function(str, spaceSeparatedOctets) {
    return str.replace(/[\s\S]/g, function(str) {
      str = ABC.zeroPad(str.charCodeAt().toString(2));
      return !1 == spaceSeparatedOctets ? str : str + " "
    })
  },
  zeroPad: function(num) {
    return "00000000".slice(String(num).length) + num
  }
};

and to be used as follows:

var binary1      = "01100110011001010110010101101100011010010110111001100111001000000110110001110101011000110110101101111001",
    binary2      = "01100110 01100101 01100101 01101100 01101001 01101110 01100111 00100000 01101100 01110101 01100011 01101011 01111001",
    binary1Ascii = ABC.toAscii(binary1),
    binary2Ascii = ABC.toAscii(binary2);

console.log("Binary 1:                   " + binary1);
console.log("Binary 1 to ASCII:          " + binary1Ascii);
console.log("Binary 2:                   " + binary2);
console.log("Binary 2 to ASCII:          " + binary2Ascii);
console.log("Ascii to Binary:            " + ABC.toBinary(binary1Ascii));     // default: space-separated octets
console.log("Ascii to Binary /wo spaces: " + ABC.toBinary(binary1Ascii, 0));  // 2nd parameter false to not space-separate octets

Source is on Github (gist): https://gist.github.com/eyecatchup/6742657

Hope it helps. Feel free to use for whatever you want (well, at least for whatever MIT permits).

Just a hint into the right direction

var foo = "TEST",
    res = [ ];

foo.split('').forEach(function( letter ) {
    var bin     = letter.charCodeAt( 0 ).toString( 2 ),
        padding = 8 - bin.length;

    res.push( new Array( padding+1 ).join( '0' ) + bin );
});

console.log( res );

var PADDING = "00000000"

var string = "TEST"
var resultArray = []

for (var i = 0; i < string.length; i++) {
  var compact = string.charCodeAt(i).toString(2)
  var padded  = compact.substring(0, PADDING.length - compact.length) + compact

  resultArray.push(padded)
}

console.log(resultArray.join(" "))

Try this:

String.prototype.toBinaryString = function(spaces = 0) {
    return this.split("").map(function(character) {
        return character.charCodeAt(0).toString(2);
    }).join(" ".repeat(spaces));
}

And use it like this:

"test string".toBinaryString(1); // with spaces
"test string".toBinaryString(); // without spaces
"test string".toBinaryString(2); // with 2 spaces

1. traverse the string
2. convert every character to their char code
3. convert the char code to binary
4. push it into an array and add the left 0s
5. return a string separated by space

Code:

function textToBin(text) {
  var length = text.length,
      output = [];
  for (var i = 0;i < length; i++) {
    var bin = text[i].charCodeAt().toString(2);
    output.push(Array(8-bin.length+1).join("0") + bin);
  } 
  return output.join(" ");
}
textToBin("!a") => "00100001 01100001"

Another way

function textToBin(text) {
  return (
    Array
      .from(text)
      .reduce((acc, char) => acc.concat(char.charCodeAt().toString(2)), [])
      .map(bin => '0'.repeat(8 - bin.length) + bin )
      .join(' ')
  );
}

8-bit characters with leading 0

'sometext'
        .split('')
        .map((char) => '00'.concat(char.charCodeAt(0).toString(2)).slice(-8))
        .join(' ');

If you need 6 or 7 bit, just change .slice(-8)

var UTF8ToBin=function(f){for(var a,c=0,d=(f=unescape(encodeURIComponent(f))).length,b="";c<d;c++){for(a=f.charCodeAt(c).toString(2);a.length%8!=0;){a="0"+a}b+=a}return b},binToUTF8=function(f){for(var a,c=0,d=f.length,b="";c<d;c+=8){b+="%"+((a=parseInt(f.substr(c,8),2).toString(16)).length%2==0?a:"0"+a)}return decodeURIComponent(b)};

This is a small minified JavaScript Code to convert UTF8 to Binary and Vice versa.

This might be the simplest you can get:

function text2Binary(string) {
    return string.split('').map(function (char) {
        return char.charCodeAt(0).toString(2);
    }).join(' ');
}