isCvnValid static method
Determines whether the card CVN is valid
@param cardCVN The credit card CVN @return true if the cvn is valid, false otherwise
Implementation
static bool isCvnValid(String cardCVN) {
if (cardCVN.isEmpty) {
return false;
}
String ccvn = cleanCvn(cardCVN);
return _isNumeric(ccvn) &&
int.parse(ccvn) >= 0 &&
ccvn.length >= 3 &&
ccvn.length <= 4;
}