Error-handling example #1

main.dart

void main() {
  try {
    sendPost();
    // on without catch clause
  } on LackOfPrivilegesException {
    print("You don't have enough privileges.");
    // on with catch clause
  } on ValidationException catch (e) {
    print('Please verify entered fields: ${e.fields}');
    // general catch clause
  } catch (e) {
    print('Error occured: $e');
  }
}

void sendPost() {
  throw LackOfPrivilegesException();
}

class LackOfPrivilegesException implements Exception {}

class ValidationException implements Exception {
  final List<String> fields;
  const ValidationException(this.fields);
}