Regex only checks first character in string C#

Question

Why does the following method only check the first character in the supplied string?

public static bool IsUnicodeSms(string message)
{
   var strMap = new Regex(@"^[@£$¥èéùìòÇØøÅå_ÆæßÉ!""#%&'()*+,-./0123456789:;<=>? ¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ§¿abcdefghijklmnopqrstuvwxyzäöñüà^{}\[~]|€]+$");
   return !strMap.IsMatch(message);
}

So for example the following string returns false: "abcლ" but "ლabc" returns true.

Plus you must escape the middle `-`, and perhaps the `\`, the `[`, and the `|` — xanatos, Apr 09 '15 at 14:49
also i'd recommend using an online tool like https://regex101.com/ to debug regex. — DLeh, Apr 09 '15 at 14:49
Here you go - `^[@£$¥èéùìòÇØøÅå_ÆæßÉ!""#%&'()*+,-./0123456789:;<=>? ¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ§¿abcdefghijklmnopqrstuvwxyzäöñüà^{}\[~\]|€]+$`. — Wiktor Stribiżew, Apr 09 '15 at 14:53

Federico Piazza · Accepted Answer · 2015-04-09T15:02:33.407

4

You have to escape ] with \] and also put the - at the end:

Change this:

var strMap = new Regex(@"^[@£$¥èéùìòÇØøÅå_ÆæßÉ!""#%&'()*+,-./0123456789:;<=>? ¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ§¿abcdefghijklmnopqrstuvwxyzäöñüà^{}\[~]|€]+$");

To this:

var strMap = new Regex(@"^[@£$¥èéùìòÇØøÅå_ÆæßÉ!""#%&'()*+,./0123456789:;<=>? ¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ§¿abcdefghijklmnopqrstuvwxyzäöñüà^{}\[~\]|€-]+$");

Btw, you can improve your regex and use:

var strMap = new Regex(@"^[@£$¥èéùìòÇØøÅå_ÆæßÉ!"#%&'()*+,./\w:;<=>? ¡ÄÖÑÜ§¿äöñüà^{}\[~\]|€-]+$");

And not sure if using the ignore case flag might help you to shorten it a little more like this:

var strMap = new Regex(@"(?i)^[@£$¥èéùìòÇøå_Ææß!"#%&'()*+,./\w:;<=>? ¡§¿äöñüà^{}\[~\]|€-]+$");

edited Apr 09 '15 at 15:02

answered Apr 09 '15 at 14:56

Federico Piazza

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1

these regexes don't match empty strings, which may be desirable – Armand Jun 11 '15 at 09:38
1

@Armand that's very easy to do, just change `]+$");` by `]*$");` – Federico Piazza Jun 11 '15 at 13:09
1

I know, just didn't want to edit your answer. I also suspect that this doesn't match the newline character, which AFAIK is a valid character. – Armand Jun 11 '15 at 14:00
1

@Armand well, this question was resolved two months ago I guess OP already solved this question, and also if he marked this answer as the right one I guess it helped too. However, thank you for pointing that. – Federico Piazza Jun 11 '15 at 14:24
3

Not getting at you. SO is a reference, as well as helping the OP with their problem. These comments are for people referring to the question in future. – Armand Jun 11 '15 at 14:58

score 2 · Answer 2 · edited May 23 '17 at 12:02

You copied the code from here.

It's very flawed. It needs more escaping. From Regexp Tutorial - Character Classes or Character Sets:

the only special characters or metacharacters inside a character class are the closing bracket (]), the backslash (\), the caret (^), and the hyphen (-)

So, it needs to be:

new Regex(@"^[@£$¥èéùìòÇØøÅå_ÆæßÉ!""#%&'()*+,\-./0123456789:;<=>? ¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑÜ§¿abcdefghijklmnopqrstuvwxyzäöñüà^{}\[~\]|€]+$");

You can of course improve the regex even further like @Fede demonstrates.

Regex only checks first character in string C#

2 Answers2

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