non_bool_operand

The operands of the operator '{0}' must be assignable to 'bool'.

The analyzer produces this diagnostic when one of the operands of either the && or || operator doesn't have the type bool.

The following code produces this diagnostic because a isn't a Boolean value:

int a = 3;
bool b = a || a > 1;

Change the operand to a Boolean value:

int a = 3;
bool b = a == 0 || a > 1;

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.