checkDigit method

  1. @override
int checkDigit(
  1. String data
)
override

Computes the check digit from data.

Implementation

@override
int checkDigit(String data) {
  if (data.length != 12) {
    throw ArgumentError('Must not be null and must contain 12 digits');
  }

  final sum1 = _compute(data, _multiplier1);
  final r1 = sum1 % 11;
  final v1 = r1 < 2 ? 0 : (11 - r1);

  final sum2 = _compute(data, _multiplier2) + (v1 * 2);
  final r2 = sum2 % 11;
  final v2 = r2 < 2 ? 0 : (11 - r2);

  return (v1 * 10) + v2;
}