assignment_to_const
Constant variables can't be assigned a value after initialization.
Description
#The analyzer produces this diagnostic when it finds an assignment to a top-level variable, a static field, or a local variable that has the const
modifier. The value of a compile-time constant can't be changed at runtime.
Example
#The following code produces this diagnostic because c
is being assigned a value even though it has the const
modifier:
const c = 0;
void f() {
c = 1;
print(c);
}
Common fixes
#If the variable must be assignable, then remove the const
modifier:
var c = 0;
void f() {
c = 1;
print(c);
}
If the constant shouldn't be changed, then either remove the assignment or use a local variable in place of references to the constant:
const c = 0;
void f() {
var v = 1;
print(v);
}
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.