CODEWITHSUNDEEP
c#linqasp.net-mvc-3
ECie
ECie

Reputation: 1477

Get days that are not present in a date range using Linq

I got a list of dates that serves as attendance like

06/01/2012
06/02/2012
06/03/2012
06/06/2012
06/07/2012
06/08/2012
06/10/2012
06/13/2012
06/14/2012
06/15/2012

and i have this date range

 06/01/2012-06/15/2012

How would i get the dates that are not on the list but falls in the date range using linq..

Upvotes: 0

Views: 162

Answers (2)

sujith karivelil
sujith karivelil

Reputation: 29026

Let inputDateList be a List of strings representing the input dates, and AttendanceDate a List of DateTime corresponds to the input strings. Let me use dateRangeStart to denote the start range and dateRangeEnd for the range End. Then following code will filter the inputDateList within the range of dateRangeStart - dateRangeEnd.

DateTime inDate;
DateTime dateRangeStart;
DateTime dateRangeEnd;
List<string> inputDateList = new List<string>(){"06/01/2012",
                                          "06/02/2012",
                                          "06/03/2012",
                                          "06/06/2012",
                                          "06/07/2012",
                                          "06/08/2012",
                                          "06/10/2012",
                                          "06/13/2012",
                                          "06/14/2012",
                                          "06/17/2012"};

List<DateTime?> AttendanceDate = inputDateList.Select(x => DateTime.TryParseExact(x, "MM/dd/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out inDate) ? inDate : (DateTime?)null)
                                              .ToList();

DateTime.TryParseExact("06/01/2012", "MM/dd/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out dateRangeStart);
DateTime.TryParseExact("06/15/2012", "MM/dd/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out dateRangeEnd);

List<DateTime?> datesInRange = AttendanceDate.Where(x => x >= dateRangeStart && x <= dateRangeEnd).ToList();

datesInRange will be the required List of dates

Upvotes: 2

Rob
Rob

Reputation: 27357

You can do something like this:

var dateList = new List<DateTime>
{
    new DateTime(2012, 06, 01),
    new DateTime(2012, 06, 02),
    //..etc
};

var startDate = new DateTime(2012, 06, 01);
var endDate = new DateTime(2012, 06, 15);

var dateRange =
    Enumerable.Range(0, (int)(endDate - startDate).TotalDays + 1)
    .Select(i => startDate.AddDays(i));

var datesNotMatched = dateRange.Except(dateList);

Upvotes: 2

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