cast_from_null_always_fails
This cast always throws an exception because the expression always evaluates to 'null'.
Description
#The analyzer produces this diagnostic when an expression whose type is Null
is being cast to a non-nullable type.
Example
#The following code produces this diagnostic because n
is known to always be null
, but it's being cast to a non-nullable type:
dart
void f(Null n) {
n as int;
}
Common fixes
#Remove the unnecessary cast:
dart
void f(Null n) {
n;
}
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.