How to convert string to binary on 7 bits? (JavaScript)

Question

I need to convert a string to binary specifically on 7 bits.

'%'.charCodeAt().toString(2)

The above code return 100101, I think it convert on 8 bits. (so this link How to convert text to binary code in JavaScript? is not helping me).

% is equal to 0100101 in binary on 7 bits.

The only links I found on SO are about Java.

What if you calculate the length of the binary and if it less than 7 bin then add zero(s) at the left of the binary number? — Sajeeb Ahamed, Jul 06 '20 at 17:09

score 5 · Accepted Answer · edited Dec 05 '21 at 20:13

5

You can use the method String.prototype.padStart()

const sevenBitBinary = (char) => char.charCodeAt().toString(2).padStart(7, '0');

console.log(sevenBitBinary('%'));

edited Dec 05 '21 at 20:13

JardonS

427
3
12

answered Jul 06 '20 at 17:14

Sajeeb Ahamed

6,070
2
21
30

if `char` have `ascii` bigger than 128 ,it will show 8 bits – Ehsan Nazeri Jul 06 '20 at 17:35

score 1 · Answer 2 · answered Jul 06 '20 at 17:10

1

You can add 0s add the beginning with .padStart.

answered Jul 06 '20 at 17:10

Jonas Wilms

132,000
20
149
151

score 0 · Answer 3 · answered Jul 06 '20 at 17:20

I think it can help you

function get7BitsBinaryString(number) {
  var result = '';
  var bits = [64, 32, 16, 8, 4, 2, 1];
  bits.forEach(bit => {
    if ((bit & number) === bit) {
      result += '1';
    } else {
      result += '0';
    }
  });
  return result;
}

console.log(get7BitsBinaryString('%'.charCodeAt()));

How to convert string to binary on 7 bits? (JavaScript)

3 Answers3