Trouble with non-capturing groups in regular expression

Question

I'm attempting to capture the 6 digit number in the following:

ObjectID: !nrtdms:0:!session:slonwswtest1:!database:TEST:!folder:ordinary,486150:

I tried the following regex:

\d+(?::$)

attempting to use a non-capturing group to strip the colon out of the returned match, but it returns the colon as in:

486150:

Any ideas what I'm doing wrong?

Answer 1

You want a positive lookahead:

\d+(?=:$)

A non-capturing group is simply a group that cannot be accessed via a backreference; they still are part of the match, nonetheless.

Alternatively, you can use

(\d+):$

and obtain the 1st match group.

Answer 2

You should use a positive lookahead rather than a non-capturing group

\d+(?=:$)