C# Regular expression Example for Integrity

Question

Can anyone tell me what this kind of Regular Expression is doing?

(\s*(\s*#\s*(?\d+)\s*))

If I test it an add whitespaces it says there is no match.

Can somebody give me an example? :)

use any online regex tool, you will have a full explanation on the right side https://regex101.com/r/xb7TTb/1 , https://regexr.com/5ov6o — Self, Mar 19 '21 at 13:24
Does this answer your question? [Reference - What does this regex mean?](https://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean) — Self, Mar 19 '21 at 13:26
Seems there was an error in the regular expression, which was then edited (not by OP) to a valid regex. I've reverted the edit, in case OP wonders why there are two different regexes now: original and [the edited one](https://regex101.com/r/xb7TTb/1) — oleksii, Mar 19 '21 at 13:29
Your regular expression is not correct. try this ```(\s*(\s*#\s*(\d+)\s*))``` — MD. RAKIB HASAN, Mar 19 '21 at 13:36

score 0 · Accepted Answer · answered Mar 19 '21 at 14:07

That regular expression is not correct. Try removing the ? character.

(\s*(\s*#\s*(\d+)\s*))

And this expression matches any number that has an # in front of it. For example, in the next lines, it matches lines 1,2,5 and 6.

1 Answers1