c# - Regular expression to extract dates from a string -

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• regex match multiple times in string 3 answers

i'm working on c# project , need parse , extract dates strings. theese strings:

dalle ore 19.30 del 04.02.2016 alle ore 19.30 del 06.02.2016
dalle ore 19.30 del 06.02.2016 alle ore 19.30 del 08.02.2016
...

for each 1 i'd extract 2 dates (ex. 04.02.2016 06.02.2016) , save 2 variables. next i'll parse them create 2 datetime objects. i'm using code:

 public static string isdate(string input)  {   regex rgx = new regex(@"\d{2}.\d{2}.\d{4}");   match mat = rgx.match(input);   if(mat.success)   return mat.tostring();   else return null;  } 

with code can extract first date not second one. how can improve regular expression? thanks!

try code below

        static void main(string[] args)         {             string[] inputs = {                  "dalle ore 19.30 del 04.02.2016 alle ore 19.30 del 06.02.2016",                   "dalle ore 19.30 del 06.02.2016 alle ore 19.30 del 08.02.2016"                              };              string pattern = @"(?'hour'\d\d).(?'minute'\d\d)\sdel\s(?'day'\d\d.\d\d.\d\d\d\d)";              foreach (string input in inputs)             {                 matchcollection matches = regex.matches(input, pattern);                 foreach (match match in matches)                 {                     timespan time = new timespan(int.parse(match.groups["hour"].value), int.parse(match.groups["minute"].value), 0);                     datetime date = datetime.parseexact(match.groups["day"].value, "mm.dd.yyyy", cultureinfo.invariantculture);                      console.writeline("time : {0}", date.add(time));                 }             }             console.readline();         } 

ok solution jdwend problem between hh.mm , date several spaces , characters. several times in form: hh:mm del dd.mm.yyyy in form dd.mm.yyyy del     dd.mm.yyyy . think still possible parse data 1 regexp or have tokenize string? thank u much!

your regular expression fine, retrieve first match. matches, use matches instead of match:

private static final regex dateregex = new regex(@"\d{2}.\d{2}.\d{4}");  public static ienumerable<string> extractdates(string input) {      return m in dateregex.matches(input).cast<match>()             select m.value.tostring(); } 

notes:

• since regex objects thread-safe , immutable, don't need rebuild every time. can store safely in static variable.

• since matches method predates .net generics, need cast<match> call cast resulting collection ienumerable<match>, can use linq.