Regex match multiple substrings inside a string

Question

So I have this one string, which contains multiple occurrences of a substring. All of these strings have the following format: <c@=someText>Content<c>

Example:

This combination of plain text and <c=@flavor> colored text<c> is valid. <c=@warning>Multiple tags are also valid.<c>

I want to extract each of the substrings via regex. However if I use the following regex <c=@.+?(?=>)>.*<c> It matches everything from the first <c... to the last <c>. What I want is each of those substrings as one item. How can I do this and if I can't do it with regex, what would be the best way to achieve my goal.

Remove `(?=>)`, and try to understand how your pattern works, you will find the solution. — Casimir et Hippolyte, Nov 13 '14 at 19:18
This might be some help: http://stackoverflow.com/questions/4892452/regex-match-multiple-times-in-string — gcarvelli, Nov 13 '14 at 19:28
@Jonesy No I want the text inside the tags, and the tags itself. — Ruhrpottpatriot, Nov 13 '14 at 19:32

Jonesopolis · Answer 1 · 2014-11-13T19:45:11.867

You can use named capture groups, along with lookaheads and lookbehinds, to grab the 'type' and 'text':

var pattern = @"(?<=<c=@)(?<type>[^>]+)>(?<text>.+?)(?=<c>)";
var str = @"This combination of plain text and <c=@flavor> colored text<c> is valid. <c=@warning>Multiple tags are also valid.<c>";

foreach (Match match in Regex.Matches(str, pattern))
{
   Console.WriteLine(match.Groups["type"].Value);
   Console.WriteLine(match.Groups["text"].Value);

   Console.WriteLine();
}

output:

flavor
 colored text

warning
Multiple tags are also valid.

pattern:

(?<=<c=@) : Look for <c=@

(?<type>[^>]+)> : Grab everything until a >, call it type

(?<text>.+?) : Grab everything until the lookahead, call it text

(?=<c>) : Stop when you find a <c>

score 1 · Accepted Answer · answered Nov 13 '14 at 20:05

1

string input = @"This combination of plain text and <c=@flavor> colored text<c> is valid. <c=@warning>Multiple tags are also valid.<c>";

var matches = Regex.Matches(input, @"<c=@(.+?)>(.+?)<c>")
                .Cast<Match>()
                .Select(m => new
                {
                    Name = m.Groups[1].Value,
                    Value = m.Groups[2].Value
                })
                .ToList();

answered Nov 13 '14 at 20:05

EZI

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This is exactly what I'm looking for. While @Jonesy also has good code, yours is more clear and has no strings to select the groups. – Ruhrpottpatriot Nov 13 '14 at 20:42

Regex match multiple substrings inside a string

2 Answers2