/Dart/Dart he default constructor is already defined. Try giving one of the constructors a name.

Dart he default constructor is already defined. Try giving one of the constructors a name.

In dart you can not have the same method/constructor name used several times 
(even with different parameters).

In your case you can either use named constructor to define 2 constructors :

class FirstClass {
  FirstClass() {}
  FirstClass.withA(a) {}
}

Source: stackoverflow.com

Similar codes

0 vote362 views1 answer
No scroll physics flutter
Dart
17 votes287 views4 answers
Cannot run with sound null safety because the following dependencies don't support null safety
Dart
0 vote314 views1 answer
Flutter iterate over list widget
Dart
2 votes356 views1 answer
Flutter clear all text in textfield
Dart
0 vote386 views1 answer
Flutter elif
Dart
0 vote369 views1 answer
UserScrollNotification in flutter
Dart
0 vote375 views1 answer
Find and update element in list dart
Dart
0 vote370 views1 answer
Flutter: How to point to localhost:8000 with the Dart http package in Flutter?
Dart
3 votes374 views2 answers
Flutter container height 100 percent
Dart
4 votes297 views2 answers
How to make a card clickable in flutter
Dart