Async programming with Dart

Future.dart

import 'dart:io';

void main() {
  performTasks();
}

void performTasks() async {
  task1();
  String output = await task2();
  task3(output);
}

void task1() {
  String result = "Task1 performed";
  DateTime dateTime = DateTime.now();
  print('$dateTime $result');
}

Future task2() async {
  Duration threeSeconds = Duration(seconds: 3);
  //sleep(duration);
  String result;

  await Future.delayed(threeSeconds, () {
    result = "Task2 result";
    DateTime dateTime = DateTime.now();
    print('$dateTime Task2 is complete and result is prepared');
  });

  return result;
}

void task3(String resultOfTask2) {
  String result = "Task3 performed";
  DateTime dateTime = DateTime.now();
  print('$dateTime $result with $resultOfTask2');
}