How to match only strings that do not contain a dot (using regular expressions)

Question

I\'m trying to find a regexp that only matches strings if they don\'t contain a dot, e.g. it matches stackoverflow, 42abc47 or a-bc-

Answer 1

^[^.]*$

or

^[^.]+$

Depending on whether you want to match empty string. Some applications may implicitly supply the ^ and $, in which case they'd be unnecessary. For example: the HTML5 input element's pattern attribute.

You can find a lot more great information on the regular-expressions.info site.