flutter async function : _Future<String> returned instead of string value when subfunction is done

Question

Trying to figure a good way to handle nested async functions I'm doing some tests with dartpad. In the following example I don't understand why _Future is printed instead of the value (level1String) ?
The output is :
toto
before await level2
before duration
after duration
13
after level 2
Instance of '_Future' // my concern is here since "after level 2" is printed I should have reached the return statement
after level 1
yeah!

import 'dart:convert';
import "dart:async";
import "dart:html";

void main() async {
  print('toto');
  await print(level1String());
  print('after level 1');
}

Future<String> level1String () async {
  print('before await level2');
   print(level2String());
  print('after level 2');
  return 'level1String';
}

int level2String () {
  print('before duration');
  Timer(Duration(seconds: 3), () {
    print('yeah!');
  });
  print('after duration');
  return 13;
}

Günter Zöchbauer · Accepted Answer · 2019-02-27 11:31:52Z

2

await print(level1String());

should be

print(await level1String());

level1String() is returning the Future you need to await, not print()

answered Feb 27, 2019 at 11:31

Günter Zöchbauer

661k235 gold badges2.1k silver badges1.6k bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

flutter async function : _Future<String> returned instead of string value when subfunction is done

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related