private_optional_parameter
Named parameters can't start with an underscore.
Description
#The analyzer produces this diagnostic when the name of a named parameter starts with an underscore.
Example
#The following code produces this diagnostic because the named parameter _x
starts with an underscore:
dart
class C {
void m({int _x = 0}) {}
}
Common fixes
#Rename the parameter so that it doesn't start with an underscore:
dart
class C {
void m({int x = 0}) {}
}
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.