verifyDigit static method

int verifyDigit(
  1. String key
)

Implementation

static int verifyDigit(String key) {
  if (key.length < 43) {
    throw FailureImpl(message: 'the key must contain 43 characters.');
  }

  const multipliers = '4329876543298765432987654329876543298765432';

  List<int> values = [];

  for (int i = 0; i < 43; i++) {
    var result = int.parse((key[i])) * int.parse(multipliers[i]);
    values.add(result);
  }

  var rest = values.reduce((value, element) => value + element) % 11;
  if (rest < 2) {
    return 0;
  }
  return 11 - rest;
}