Question

I have a collection of DateTime named reportLogs. I need to create a Collection<T> of ShortDateString from this Collection<DateTime>. What is the most efficient way to do it?

Collection<DateTime> reportLogs =  reportBL.GetReportLogs(1, null, null);
Collection<string> logDates = new Collection<string>();
foreach (DateTime log in reportLogs)
{
    string sentDate = log.ToShortDateString();
    logDates.Add(sentDate);
}

EDIT:

The question is about Collection of string; not about List of string. How can we handle the Collection of string ?

REFERENCE:

1. Using LINQ to convert List<U> to List<T>
2. LINQ convert DateTime to string
3. Convert a datetime in a subcollection of collection and use it in LINQ to SQL
4. convert Collection<MyType> to Collection<Object>

Answer 1

If you’re happy with just IEnumerable<string>:

IEnumerable<string> logDates = reportBL.GetReportLogs(1, null, null)
                                      .Select(d => d.ToShortDateString());

You could turn this to List<string> easily with 1 more call

List<string> logDates = reportBL.GetReportLogs(1, null, null)
                                      .Select(d => d.ToShortDateString())
                                      .ToList();

Edit: If you really need your object to be Collection<T> then that class has a constructor which takes IList<T> so the following will work:

Collection<string> logDates = new Collection(reportBL.GetReportLogs(1, null, null)
                                      .Select(d => d.ToShortDateString())
                                      .ToList());