LINQ question

Hello EE ...  I got a linq expression in vb.net like this :

  Dim q = (From m In MyItems
                    Where arrString.All(Function(v) m.Value.Contains(v))
                    Order By m.Key Descending
                    Select m)

the first item in ever rows in q is a datevalue.

How could I modify that LINQ expression so that in q I would get the number of days difference between each rows instead of every datevalue ?
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PhilippeRenaudAsked:
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Fernando SotoRetiredCommented:
Hi PhilippeRenaud;

You will not be able to do it in the Linq query itself because Linq will not know what the next date will be until after it has already created/processed the current object.

What you can do is first apply the ToList() method to the query, like this:
Dim q = (From m In MyItems
                Where arrString.All(Function(v) m.Value.Contains(v))
                Order By m.Key Descending
                Select m).ToList()

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this is because Linq is a deferred execution operation, meaning it does not create a result set until it has been enumerated over or use a method such as ToList. Then you can use a For loop and for each iteration use DateDiff on the current object and access the next by using the current index plus 1. Depending on the data type of the object holding the date you might have to add an extra property to the object to hold the number of days, because of the date is a DateTime object it will not hold an integer.
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PhilippeRenaudAuthor Commented:
trhanks
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