Regex with exception of particular words

Question

I have problem with regex. I need to make regex with an exception of a set of specified words, for example: apple, orange, juice. and given these words, it will match everyt

Answer 1

\A(?!apple\Z|juice\Z|orange\Z).*\Z

will match an entire string unless it only consists of one of the forbidden words.

Alternatively, if you're not using Ruby or you're sure that your strings contain no line breaks or you have set the option that ^ and $ do not match on beginnings/ends of lines

^(?!apple$|juice$|orange$).*$

will also work.