How to add an attribute containing invalid characters to a model in Yii2?

Question

Yii

Hello.
It is necessary to add and validate a field containing a minus sign -> '-'.
How can this be checked?
UPD: you need to fill in the form with data and validate it. If the attribute is not added, then an exception is thrown - [yii\base\UnknownPropertyException]

Answer 1

$foo->{'foo-bar'} = 'something';
but it's better not to.