not_a_type

{0} isn't a type.

The analyzer produces this diagnostic when a name is used as a type but declared to be something other than a type.

The following code produces this diagnostic because f is a function:

f() {}
g(f v) {}

Replace the name with the name of a type.

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.