invalid_ use_ of_ null_ value
An expression whose value is always 'null' can't be dereferenced.
Description
#
The analyzer produces this diagnostic when an expression whose value will
always be
null
is dereferenced.
Example
#
The following code produces this diagnostic because
x
will always be
null
:
int f(Null x) {
return x.length;
}
Common fixes
#
If the value is allowed to be something other than
null
, then change the
type of the expression:
int f(String? x) {
return x!.length;
}
Unless stated otherwise, the documentation on this site reflects Dart 3.9.2. Page last updated on 2025-9-1. View source or report an issue.