Czech bank account number validity check / Kontrola validnosti českého čísla účtu

CzechBankAccountCheck.js

function checkBankAccountNumber(account) {
  var matches = /^(([0-9]{0,6})-)?([0-9]{1,10})\/([0-9]{1,6})$/.exec(account);

  if (!matches) {
    return false;
  }
  
  return checkDigit11(matches[2]) && checkDigit11(matches[3]);
}

function checkDigit11(n, x) {

  var l = n.length - 1, i = 0, v = 0;
  var weights = [1, 2, 4, 8, 5, 10, 9, 7, 3, 6]; 

  for(i = 0; i <= l; i++) {
    console.log(i, n[l-i], weights[i], );
    v += parseInt(n[l-i], 10) * weights[i]; 
  }

  return v%11 == 0;
};

checkBankAccountNumber('123456-1234567890/1234');