always_put_required_named_parameters_first

Required named parameters should be before optional named parameters.

The analyzer produces this diagnostic when required named parameters occur after optional named parameters.

The following code produces this diagnostic because the required parameter x is after the optional parameter y:

void f({int? y, required int x}) {}

Reorder the parameters so that all required named parameters are before any optional named parameters:

void f({required int x, int? y}) {}

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.