Convert result of matches from regex into list of string

Question

How can I convert the list of match result from regex into List? I have this function but it always generate an exception,

Answer 1

With the Regex you have, you need to use Regex.Matches to get the final list of strings like you want:

MatchCollection matchList = Regex.Matches(Content, Pattern);
var list = matchList.Cast<Match>().Select(match => match.Value).ToList();

Answer 2

var regex = new Regex("{([A-Za-z])*}");
var result= regex.Matches(text).Where(p => p.Success).Select(p => p.Value).ToList();

Answer 3

A possible solution using Linq:

using System.Linq;
using System.Text.RegularExpressions;

static class Program {
    static void Main(string[] aargs) {
        string value = "I have a dog and a cat.";
        Regex regex = new Regex("dog|cat");
        var matchesList = (from Match m in regex.Matches(value) select m.Value).ToList();
    }
}

Answer 4

Here's another solution that will fit into your code well.

while (_matchList.Success)
{
    _returnValue.Add(_matchList.Value);
    _matchList = _matchList.NextMatch();
}

Answer 5

To get just a list of Regex matches, you may:

var lookfor = @"something (with) multiple (pattern) (groups)";
var found = Regex.Matches(source, lookfor, regexoptions);
var captured = found
                // linq-ify into list
                .Cast<Match>()
                // flatten to single list
                .SelectMany(o =>
                    // linq-ify
                    o.Groups.Cast<Capture>()
                        // don't need the pattern
                        .Skip(1)
                        // select what you wanted
                        .Select(c => c.Value));

This will "flatten" all the captured values down to a single list. To maintain capture groups, use Select rather than SelectMany to get a list of lists.

Answer 6

Historically the Regex collections have not implemented the generic collection interfaces, and the LINQ extension methods you're using operate on the generic interfaces. MatchCollection was updated in .NET Core to implement IList, and thus can be used with the Selectextension method, but when you move to .NET Standard 2.0, that interface implementation isn't there, and thus you can't just callSelect. Instead, you'll need to use the LINQ Cast or OfType extensions to convert to an IEnumerable, and then you can use Select on that. Hope that helps.

Example

Regex wordMatcher = new Regex(@"\p{L}+");
return wordMatcher.Matches(text).Cast<Match>().Select(c => c.Value);

Regex wordMatcher = new Regex(@"\p{L}+");
return wordMatcher.Matches(text).OfType<Match>().Select(c => c.Value);