Regular expression to not match "www".

Question

I guess I'm getting really weak in logic.

I need to write a regular expression which matches everything except www. It should match wwwd, abcd and everything else, just not www. (Oh God, please, it shouldn't be very easy).

I'm using Ruby language's implementation of regular expression.

UPDATE: I need to use regular expression and not just text != 'www' because it is the way API is designed. It expects a pattern as argument and not the result.

Answer 1

Why regex? Isn't text != "www" enough?

Here it is nonetheless (uses look-ahead): ^(?!www$).*

Answer 2

This is a plain vanilla regex. There are fancier things you can do with negative assertions in certain dialects.

^(.|..|[^w]..|.[^w].|..[^w]|.....*)$

In English:

You want something that's exactly one character, exactly two characters, exactly three characters where at least one of those 3 is not a w, or more than 3 characters long.

Answer 3

Same general idea as Laurence Gonsalves(*), but it seems to me one could say ^.$|^..$|^....+$|.*[^w].* That is, 1 or 2 or more than 3 characters between start and end, or any number containing a non-w.

(*) I really meant this to be a comment on his answer, but accidentally posted it as my own answer. I guess I'll just leave it here.

Answer 4

Just another approach

^.{0,2}([^w].*|.{4,})?$