isValidNIE static method
- String nie
Validates NIE format
Implementation
static bool isValidNIE(String nie) {
if (nie.length != 9) return false;
final first = nie[0].toUpperCase();
if (!['X', 'Y', 'Z'].contains(first)) return false;
// Replace X=0, Y=1, Z=2, then validate as DNI
final normalized =
nie.replaceFirst(first, {'X': '0', 'Y': '1', 'Z': '2'}[first]!);
return isValidDNI(normalized);
}