Validace IČ

registrationNumberValidator.js

export function registrationNumberValidator(regNr) {
  if (!regNr || (typeof regNr !== "string") || regNr.length !== 8) return false;
  const [n8, n7, n6, n5, n4, n3, n2, x] = regNr.split("").map(Number);
  return (
    x ===
    (11 -
      ((8 * n8 + 7 * n7 + 6 * n6 + 5 * n5 + 4 * n4 + 3 * n3 + 2 * n2) % 11)) %
      10
  );
}