Recommended way from dart team to catch errors when using await in Flutter

Question

I write a lot of async code that uses await to handle Futures.

If I have

() async {
  var result = await someFuture();
}

what would be the preferred way to catch errors. Wraping the code in try/catch or doing

() async {
  var result = await someFuture().catch(_errorHandler);
}

EDIT:

Also, if I have many await calls in one async method, what is the preferred catch all the errors instead of writing .catchError for eachOne.

() async {
  var result = await someFuture();
  var result2 = await someFuture2();
  var result3 = await someFuture3();

}

I suppose that when using try and catch your code would not continue executing, but continuing in the catch block after an exception is thrown. However, it will continue if you catch it like you proposed. — creativecreatorormaybenot
– creativecreatorormaybenot, Commented Jun 3, 2018 at 21:30
Questions that can be qualified as "Primarily opinion based" don't fit stackoverflow. As they don't have a finite answer. — Rémi Rousselet
– Rémi Rousselet, Commented Jun 4, 2018 at 2:58

mickmackusa · Accepted Answer · 2025-10-15 08:10:55Z

19

According to the Dart docs if you use await wrap it in a try-catch

edited Oct 15 at 8:10

mickmackusa♦

49.2k13 gold badges98 silver badges165 bronze badges

answered Jun 4, 2018 at 13:54

Thomas

9,3477 gold badges33 silver badges50 bronze badges

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

5 Comments

Johan Walhout Over a year ago

Hi Thomas, I think your right, but when I look at the documentation: dart.dev/guides/libraries/futures-error-handling I don't see any example of that. Can you maybe share an example you use or to the the documentation? Just curious :)

Martin Braun Over a year ago

So, a Future.error(...) within the async function will be catched by the outer try/catch?

Thomas Over a year ago

nope, they won't

IceFire Over a year ago

Huh? What is the point then?

Thomas Over a year ago

you have to await the call inside a try-catch. if you have a Future.error that will receive the exception and not the try catch around it

Iain Smith · Accepted Answer · 2022-09-13 15:46:41Z

3

The Docs suggest just wrapping in a try-catch

Example code:

try {
  print('Awaiting user order...');
  var order = await fetchUserOrder();
} catch (err) {
  print('Caught error: $err');
}

Reference also has a runnable example https://dart.dev/codelabs/async-await#handling-errors

answered Sep 13, 2022 at 15:46

Iain Smith

9,7334 gold badges52 silver badges63 bronze badges

Comments

Akumbom · Accepted Answer · 2025-10-15 14:51:13Z

0

The docs recommend using try-catch for error handling, just as you would in synchronous code https://dart.dev/libraries/async/async-await#handling-errors
Additionally, if you need code to execute regardless of whether an exception occurs, wrap it in finally block https://dart.dev/language/error-handling#finally

Example:

try{
  var result = await someFuture();
  var result2 = await someFuture2();
  var result3 = await someFuture3();
}catch(e){
  print('Error: $e');
}finally{
   print('Done')
}

answered Oct 15 at 14:51

Akumbom

215 bronze badges

Collectives™ on Stack Overflow

Recommended way from dart team to catch errors when using await in Flutter

3 Answers 3

5 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

5 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related