Regex for alphanumeric password, with at least 1 number and character

Question

Need help with a regex for alphanumeric password, with at least 1 number and character, and the length must be between 8-20 characters.

I have this but doesn\'t seem

Answer 1

Wouldn't it be better to do this validation with some simple string functions instead of trying to shoehorn a difficult to validate regex into doing this?