use_late_for_private_fields_and_variables

Use late for private members with a non-nullable type.

Use late for private members with non-nullable types that are always expected to be non-null. Thus it's clear that the field is not expected to be null and it avoids null checks.

BAD:

int? _i;
m() {
  _i!.abs();
}

GOOD:

late int _i;
m() {
  _i.abs();
}

OK:

int? _i;
m() {
  _i?.abs();
  _i = null;
}

To enable the use_late_for_private_fields_and_variables rule, add use_late_for_private_fields_and_variables under linter > rules in your analysis_options.yaml file:

linter:
  rules:
    - use_late_for_private_fields_and_variables

If you're instead using the YAML map syntax to configure linter rules, add use_late_for_private_fields_and_variables: true under linter > rules:

linter:
  rules:
    use_late_for_private_fields_and_variables: true

Unless stated otherwise, the documentation on this site reflects Dart 3.6.2. Page last updated on 2025-01-27. View source or report an issue.