learn.dart

import 'dart:async';

main() {
  print(1);
  futureNoDelay(2).then(print);
  future(3).then(print);
  futureSync(4).then(print);
  futureSyncReturnFuture(5).then(print);
  futureSyncReturnFutureValue(6).then(print);
  futureValue(7).then(print);
  scheduleMicrotask(() => print(8));
  print(9);
}

Future<int> futureNoDelay(int value) =>
    Future.delayed(Duration.zero, () => value);

Future<int> future(int value) => Future(() => value);

Future<int> futureSync(int value) => Future.sync(() => value);

Future<int> futureSyncReturnFuture(int value) =>
    Future.sync(() => Future(() => value));

Future<int> futureSyncReturnFutureValue(int value) =>
    Future.sync(() => Future.value(value));

Future<int> futureValue(int value) => Future.value(value);