How to access last element value in query syntax?

Suppose I have this class:-

public class Availability
    {
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
    }

And a collection based on it:-

List availability = new List
{
      new Availability { StartDate = new DateTime(2015,1,5), EndDate = new DateTime(2015,1,10)},
      new Availability { StartDate = new DateTime(2015,1,15), EndDate = new DateTime(2015,1,20)},
      new Availability { StartDate = new DateTime(2015,1,22), EndDate = new DateTime(2015,1,28)}
};

Now, I am trying to write some query,(that query is very big

but I need help for particulat scenario)

var result = //Other query
from a in availability
where d < a.StartDate && d > ??

At "??" I want to access EndDate of last accessed list i.e. when query

is running for first object (05/Jan, 10/Jan) since it is first object

in collection I don't have any filter but when query is executing

second object i.e (15/Jan, 20/Jan) I want to access 10/Jan (EndDate

of last accessed object. But, `a` will currently hold the object with

date (15/Jan, 20/Jan) How to access previous one? I hope I am clear.

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes11y ago
Accepted answer
Try this:

var result = availability.Where((a, i) =>
{
if (i == 0) return false; // skip first element
Availability prev = availability[i - 1];
return d < a.StartDate && d > prev.EndDate;
});

0
Vulpes11y ago
Yep, there's always more than one way to do stuff with LINQ :)
0
Rahul Singh11y ago
Thank You @Vulpes, I was expecting you to answer this question and you did :)Although after posting the question, I did it with Select Overload like this:-

availability.Select((v,i) => new { Value = v, Index = i})

and it worked.

Thank You.
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