Pfthb

function stringToBinary(input) 
 var characters = input.split('');

 return characters.map(function(char) 
 return char.charCodeAt(0).toString(2)
 ).join('');


alert(stringToBinary('test'))

function binaryToString(input) 
 var bits = input.split('');
 
 var byte = '';
 return bits.map(function(bit) 
 byte = byte + bit;
 
 if (byte.length == 8) 
 var char = byte; // how can I convert this to a character again?
 byte = '';
 return char;
 
 
 return '';
 ).join('');


alert(binaryToString('1110100110010111100111110100'));

function stringToBinary(input) 
 var characters = input.split('');

 return characters.map(function(char) 
 const binary = char.charCodeAt(0).toString(2)
 const pad = Math.max(8 - binary.length, 0);
 // Just to make sure it is 8 bits long.
 return '0'.repeat(pad) + binary;
 ).join('');


function binaryToString(input) 
 let bytesLeft = input;
 let result = '';

 // Check if we have some bytes left
 while (bytesLeft.length) 
 // Get the first digits
 const byte = bytesLeft.substr(0, 8);
 bytesLeft = bytesLeft.substr(8);

 result += String.fromCharCode(parseInt(byte, 2));
 

 return result;


const binary = stringToBinary('test');
console.log(binaryToString(binary));

function stringToBinary(input) 
 var characters = input.split('');

 return characters
 .map(function(char) 
 return char.charCodeAt(0).toString(2).padStart(8, 0)
 )
 .join(' '); // show with space for each byte
 // watch leading zero, which is missed in the former code


console.log(stringToBinary('test'))

function binaryToString(input) 
 return input
 .match(/.8/g) // take 8 characters
 .map(function(byte) 
 return String.fromCharCode(parseInt(byte, 2));
 )
 .join('');


console.log(binaryToString('01110100011001010111001101110100'));

function binaryToString(input) 
 return String
 .fromCharCode(...input
 .match(/.8/g)
 .map(byte => parseInt(byte, 2))
 );


console.log(binaryToString('01110100011001010111001101110100'));