main.dart

import 'dart:async';

void main() async {
  print('start');
  try {
    doSomething().then((e) {
      print('e: $e');
    }).catchError((e) {
      print('catchError: $e');
    });
  } catch (e) {
    print('caught exception: $e');
  }
  print('end');
}

Future<String> doSomething() async {
  await Future.delayed(Duration(seconds: 1));
  throw Exception('Exception!');
}