no_duplicate_case_values

Don't use more than one case with same value.

DON'T use more than one case with same value.

This is usually a typo or changed value of constant.

BAD:

const int A = 1;
switch (v) {
  case 1:
  case 2:
  case A:
  case 2:
}

GOOD:

const int A = 1;
switch (v) {
  case A:
  case 2:
}

NOTE: this lint only reports duplicate cases in libraries opted in to Dart 2.19 and below. In Dart 3.0 and after, duplicate cases are reported as dead code by the analyzer.

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

linter:
  rules:
    - no_duplicate_case_values

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

linter:
  rules:
    no_duplicate_case_values: true

Unless stated otherwise, the documentation on this site reflects Dart 3.6.0. Page last updated on 2025-01-27. View source or report an issue.