Question

Sort of a two part question:

1. Is there any theoretical regular expression that will never match any string (using general syntax without any fancy stuff provided by modern regular expression matchers)?
2. Is there a simple way to use C#’s Regex syntax to create a regex that will never match any string (this time, all the fancy stuff is included)?

NOTE: I am not referring to matching the empty string (that would be easy, just "").

Answer 1

Just as you can match any characters with [\s\S], you can match no characters with [^\s\S] (or [^\w\W], etc).