visaCard static method
Validates whether the given cardNumber
is a valid Visa card number.
The cardNumber
parameter should be a string representing a Visa card number.
Returns true
if the cardNumber
is valid, false
otherwise.
Implementation
static bool visaCard(String cardNumber) {
String pattern = r'^4[0-9]{12}(?:[0-9]{3})?$';
RegExp regExp = RegExp(pattern);
return regExp.hasMatch(cardNumber);
}