CODEWITHSUNDEEP
c#linqdatetime
Mike
Mike

Reputation: 301

Comparing against list of dates

Have a small problem with LINQ queries.

Basically I have two lists, filled with dates.

List<DateTime> start = GetListOfStartDates();
List<DateTime> end = GetListOfEndDates();
DateTime date = new DateTime(2012, 1, 1);

How do I perform a LINQ query, where I compare a date against the start and end date, basically in sense: 

(start <= date && end >= date)

Obviously I understand that they are lists, so this does not work, how do I compare a single date against two lists of dates? Basically doing a between for a set of dates.

The start indices will always match end indices, start[7] will always match end[7]. I'm attempting to turn a mysql between-query into LINQ. So I'm looking for IF the given "date" is within any start-end pair.

Upvotes: 1

Views: 314

Answers (3)

abatishchev
abatishchev

Reputation: 100366

Another interpretation of OP's goal:

bool b = start.Zip(end, (x, y) => new { Start = x, End = y })
              .Any(z => z.Start <= date && z.End >= date);

Or you can use All() instead, that depends on your logic.

Upvotes: 3

Tim Copenhaver
Tim Copenhaver

Reputation: 3302

Assuming I'm interpreting your question correctly (see my comment above) I think you are better off doing this as a for loop instead of a LINQ query. I'd do something like this:

public bool DateFallsInRange(IEnumerable<DateTime> startDates, IEnumerable<DateTime> endDates)
{
    for (int index = 0; index < startDates.Count; index++)
    {
        if ((startDates[index] <= compareDate) && (compareDate <= endDates[index])) return true;
    }
    return false;
}

Upvotes: 2

Tobia Zambon
Tobia Zambon

Reputation: 7639

the start and end list index must be the same? Example:

start|end
[0]1940|1950
[1]1890|1930

the date 1931 should pass because 1890<1931<1950? or should not pass because 1931<1940 and 1931>1930?

Upvotes: 0

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