prefer_const_declarations

Use 'const' for final variables initialized to a constant value.

The analyzer produces this diagnostic when a top-level variable, static field, or local variable is marked as final and is initialized to a constant value.

The following code produces this diagnostic because the top-level variable v is both final and initialized to a constant value:

final v = const <int>[];

The following code produces this diagnostic because the static field f is both final and initialized to a constant value:

class C {
  static final f = const <int>[];
}

The following code produces this diagnostic because the local variable v is both final and initialized to a constant value:

void f() {
  final v = const <int>[];
  print(v);
}

Replace the keyword final with const and remove const from the initializer:

class C {
  static const f = <int>[];
}

Unless stated otherwise, the documentation on this site reflects Dart 3.8.0. Page last updated on 2025-05-08. View source or report an issue.