Regex that does not allow consecutive dots

Question

I have a Regex to allow alphanumeric, underscore and dots but not consecutive dots:

^(?!.*?[.]{2})[a-zA-Z0-9_.]+$

I also need to now allow

Answer 1

You can try this:

^(?!.*\.\.)[A-Za-z0-9_.]+$

This will not allow any consecutive dots in the string and will also allow dot as first and last character

Tried here