Create a validator in flutter

TextFormField(
  // The validator receives the text that the user has entered.
  validator: (value) {
    if (value.isEmpty) {
      return 'Please enter some text';
    }
    return null;
  },
);

Source: flutter.dev

Similar codes

3 votes219 views1 answer
Android studio emulator blue screen windows 10
Dart
1 vote211 views2 answers
Dart round
Dart
4 votes218 views1 answer
Getters and setters dart
Dart
4 votes239 views1 answer
Flutter cliprrect
Dart
0 vote248 views1 answer
Flutter getx arguments
Dart
14 votes199 views2 answers
Dart try catch
Dart
1 vote209 views1 answer
Flutter performance timer
Dart
0 vote211 views1 answer
Dart iterable firstWhere
Dart
0 vote219 views1 answer
Flutter compute
Dart
1 vote220 views1 answer
Flutter text hint
Dart