LINQ with Skip and Take

c# linq skip take
user1618825 picture user1618825 · Mar 13, 2013 · Viewed 82.7k times · Source

I used the below code to take some items from IEnumerable, but it is always returning the source as null and count as 0 and actually there are items exists in IEnumerable

private void GetItemsPrice(IEnumerable<Item> items, int customerNumber)
{
    var a = items.Skip(2).Take(5);
}

When i try to access a it has count 0. Anything goes wrong here?

enter image description here

Answer

Sergey Berezovskiy picture Sergey Berezovskiy · Mar 13, 2013

Remember, that variable a in your code is a query itself. It is not result of query execution. When you are using Immediate Window to watch query (actually that relates to queries which have deferred execution otherwise you will have results instead of query), it will always show 

{System.Linq.Enumerable.TakeIterator<int>}
    count: 0
    source: null

You can verify that with this code, which obviously has enough items:

int[] items = { 1, 2, 3, 4, 5, 6, 7 };
var a = items.Skip(2).Take(3);

So, you should execute your query to see results of query execution. Write in Immediate Window:

a.ToList()

And you will see results of query execution:

Count = 3
    [0]: 3
    [1]: 4
    [2]: 5

Related questions

LINQ: How to skip one then take the rest of a sequence

i would like to iterate over the items of a List<T>, except the first, preserving the order. Is there an elegant way to do it with LINQ using a statement like: foreach (var item in list.Skip(1).…

Read More
Group by in LINQ

Let's suppose if we have a class like: class Person { internal int PersonID; internal string car; } I have a list of this class: List<Person> persons; And this list can have multiple instances with same PersonIDs, for example: …

Read More
LINQ query on a DataTable

I'm trying to perform a LINQ query on a DataTable object and bizarrely I am finding that performing such queries on DataTables is not straightforward. For example: var results = from myRow in myDataTable where results.Field("RowNo") == 1 select results; This …

Read More