Regex: How to match a string that is not only numbers

Question

Is it possible to write a regular expression that matches all strings that does not only contain numbers? If we have these strings:

• abc

Answer 1

If we want to restrict valid characters so that string can be made from a limited set of characters, try this:

(?!^\d+$)^[a-zA-Z0-9_-]{3,}$

or

(?!^\d+$)^[\w-]{3,}$

/\w+/: Matches any letter, number or underscore. any word character