Regex: Do not match if pattern at the end of the string

Question

I have the following regex, where I want to match any explicit dot followed by one or more:

<b> <i> <u> </b> </i> </u>

I would like this Regex to NOT match this pattern if it occurs at the end of the string.

string = Regex.Replace(string, "\.((<[\/biu]+>)+)", ".$1||")

Ex:

This <b>should match.</b> allright.

This <i><b>shouldn't match.</b></i>

Answer 1

"\.((<[\/biu]+>)+)(?!$)"

Use the negative lookahead assertion with the $ symbol to check for end of line. (Remember, $ matches end of line so you want to not match that.)

Answer 2

Force there to be more items after the last closed element, but make sure they aren't elements themselves.

"\.((<[\/biu]+>)+)[^<>]+"

Answer 3

You could use atomic grouping:

\.(?>(?:<\/?[biu]>)+)(?!$)