Matching when an arbitrary pattern appears multiple times

Question

I\'m trying to write a regex that will succeed when an arbitrary pattern of length 2 or greater appears more than once in a phrase. Essentially, I would like to use a capture gr

Answer 1

You can use this lookahead based regex:

(.{2,})(?=.*?\1)

RegEx Demo

Explanation:

.{2,}     # any 2 or more characters
(.{2,})   # group them into captured group #1
(?=...)   # positive lookahead
(?=.*?\1) # make sure at least one occurrence of captured group #1