set_element_type_not_assignable

The element type '{0}' can't be assigned to the set type '{1}'.

The analyzer produces this diagnostic when an element in a set literal has a type that isn't assignable to the element type of the set.

The following code produces this diagnostic because the type of the string literal '0' is String, which isn't assignable to int, the element type of the set:

var s = <int>{'0'};

If the element type of the set literal is wrong, then change the element type of the set:

var s = <String>{'0'};

If the type of the element is wrong, then change the element:

var s = <int>{'0'.length};

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.