future in flutter code example

Example 1: flutter future return error

// Catch it with catchError()
return Future.error("This is the error", StackTrace.fromString("This is its trace"));

Example 2: dart language asynchronous ??

import 'dart:async';

void main() {
  final myFuture = Future(() {
    print("Hello from the future!");
    return true;
  });

  print("Done!");
}