Asp.net ValidationExpression

Question

I'm looking for ValidationExpression to allow entering 9 or 10 or 11 or 12 digits.

I used these Expressions but did not work with me.

"\d{9}|\d{10}|\d{11}|\d{12}" "\d{9}|d{10}|d{11}|d{12}" "\d{9}?|d{10}?|d{11}?|d{12}?"

any advice?

Answer 1

"^\d{9,12}$" should work.