Question

I have the below function

public static List<DateTime> GetOnlyFridays(DateTime endDate, int weeks, bool isIncludeBaseDate)
{
    //Get only the fridays from the date range
    List<DateTime> dtlist = new List<DateTime>();

    List<DateTime> tempDtlist = (from dtFridays in GetDates(endDate, weeks)
                                 where dtFridays.DayOfWeek == DayOfWeek.Friday
                                 select dtFridays).ToList();

    if (isIncludeBaseDate)
    {
        dtlist = tempDtlist.Skip(1).ToList();
        dtlist.Add(endDate);
    }
    else
    {
        dtlist = tempDtlist;
    }

    return dtlist;
}

What basically I am doing is getting the datelist using the GetDates function and then depending on the isIncludeBaseDate bool value(if true) skipping the last date and adding the Base Date

It is working fine but can this program can be improve?

I am using C#3.0 and Framework 3.5

Thanks

Answer 1

You’re doing too many temporary list-conversions; you can keep all the work as a query until the very end, that way it’ll only be evaluated once.

public static List<DateTime> GetOnlyFridays(DateTime endDate, int weeks, bool isIncludeBaseDate)
{
    var fridays = GetDates(endDate, weeks)
                    .Where(d => d.DayOfWeek == DayOfWeek.Friday);
    if (isIncludeBaseDate)
    {
        fridays = fridays.Skip(1)
                         .Concat(new []{endDate});
    }
    return fridays.ToList();
}