Aggregation
Aggregate, Average, Count, LongCount, Max, Min, Sum
Conversion
AsEnumerable, Cast, OfType, ToArray, ToDictionary, ToList, ToLookup
Element
ElementAt, ElementAtOrDefault, First, FirstOrDefault, Last, LastOrDefault, Single, SingleOrDefault
ElementAt
ElementAtOrDefault
First (simple)
First (conditional)
FirstOrDefault
Last
LastOrDefault (simple)
LastOrDefault (conditional)
Single
SingleOrDefault
Generation
DefaultIfEmpty, Empty, Range, Repeat
Grouping
GroupBy
Join
GroupJoin, Join
Ordering
OrderBy, OrderByDescending, Reverse, ThenBy, ThenByDescending
OrderBy (simple - numbers)
OrderBy (simple - dates)
OrderBy (simple - objects)
OrderByDescending
Reverse
ThenBy
ThenByDescending
Other
Concat, SequenceEqual, Zip
Partitioning
Skip, SkipWhile, Take, TakeWhile
Projection
Select, SelectMany
Quantifiers
All, Any, Contains
Restriction
Where
Set
Distinct, Except, Intersect, Union
Close
Count: Returns the number of elements in a collection.
| Count: Returns the number of elements in a collection. |
| Count: Returns the number of elements in a collection. |
| This Lambda Expression sample counts names in array. |
| This Lambda Expression sample counts names in array. |
// A Query Expression cannot be constructed for Count() in C#. // Consider using a Lambda Expression instead.
Private Shared Sub Sample_Count_Linq()
Dim names As String() = {"Peter", "John", "Kathlyn", "Allen", "Tim"}
Dim result = Aggregate n In names Into Count()
Debug.WriteLine("Counting names gives:")
Debug.WriteLine(result)
End Sub
Output: Counting names gives: 5
let Sample_Count_Linq() =
let names = [|"Peter"; "John"; "Kathlyn"; "Allen"; "Tim"|]
let result = query {
for n in names do
count
}
Debug.WriteLine(sprintf "Counting names gives:")
Debug.WriteLine(sprintf "%d" result)
Output: Counting names gives: 5
static void Sample_Count_Lambda()
{
string[] names = { "Peter", "John", "Kathlyn", "Allen", "Tim" };
var result = names.Count();
Debug.WriteLine("Counting names gives:");
Debug.WriteLine(result);
}
Output: Counting names gives: 5
Private Shared Sub Sample_Count_Lambda()
Dim names As String() = {"Peter", "John", "Kathlyn", "Allen", "Tim"}
Dim result = names.Count()
Debug.WriteLine("Counting names gives:")
Debug.WriteLine(result)
End Sub
Output: Counting names gives: 5
let Sample_Count_Lambda() =
let names = [|"Peter"; "John"; "Kathlyn"; "Allen"; "Tim"|]
let result = names.Count()
Debug.WriteLine(sprintf "Counting names gives:")
Debug.WriteLine(sprintf "%d" result)
Output: Counting names gives: 5