aichholzer

const ced = '0931811087';

let [suma, mul, chars] = [0, 1, ced.length];
for (let index = 0; index < chars; index += 1) {
  let num = ced[index] * mul;
  suma += num - (num > 9) * 9;
  mul = 1 << index % 2;
}

if ((suma % 10 === 0) && (suma > 0)) {