prefer_adjacent_string_concatenation

String literals shouldn't be concatenated by the '+' operator.

The analyzer produces this diagnostic when the + operator is used to concatenate two string literals.

The following code produces this diagnostic because two string literals are being concatenated by using the + operator:

var s = 'a' + 'b';

Remove the operator:

var s = 'a' 'b';

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.