unnecessary_question_mark

The '?' is unnecessary because '{0}' is nullable without it.

The analyzer produces this diagnostic when either the type dynamic or the type Null is followed by a question mark. Both of these types are inherently nullable so the question mark doesn't change the semantics.

The following code produces this diagnostic because the question mark following dynamic isn't necessary:

dynamic? x;

Remove the unneeded question mark:

dynamic x;

Unless stated otherwise, the documentation on this site reflects Dart 3.7.3. Page last updated on 2025-05-08. View source or report an issue.