Enumerable.Take Method
Definition
Important
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Overloads
Take<TSource>(IEnumerable<TSource>, Int32) |
Returns a specified number of contiguous elements from the start of a sequence. |
Take<TSource>(IEnumerable<TSource>, Range) |
Returns a specified range of contiguous elements from a sequence. |
Take<TSource>(IEnumerable<TSource>, Int32)
- Source:
- Take.cs
- Source:
- Take.cs
- Source:
- Take.cs
Returns a specified number of contiguous elements from the start of a sequence.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Collections::Generic::IEnumerable<TSource> ^ Take(System::Collections::Generic::IEnumerable<TSource> ^ source, int count);
public static System.Collections.Generic.IEnumerable<TSource> Take<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, int count);
static member Take : seq<'Source> * int -> seq<'Source>
<Extension()>
Public Function Take(Of TSource) (source As IEnumerable(Of TSource), count As Integer) As IEnumerable(Of TSource)
Type Parameters
- TSource
The type of the elements of source
.
Parameters
- source
- IEnumerable<TSource>
The sequence to return elements from.
- count
- Int32
The number of elements to return.
Returns
An IEnumerable<T> that contains the specified number of elements from the start of the input sequence.
Exceptions
source
is null
.
Examples
The following code example demonstrates how to use Take to return elements from the start of a sequence.
int[] grades = { 59, 82, 70, 56, 92, 98, 85 };
IEnumerable<int> topThreeGrades =
grades.OrderByDescending(grade => grade).Take(3);
Console.WriteLine("The top three grades are:");
foreach (int grade in topThreeGrades)
{
Console.WriteLine(grade);
}
/*
This code produces the following output:
The top three grades are:
98
92
85
*/
' Create an array of Integer values that represent grades.
Dim grades() As Integer = {59, 82, 70, 56, 92, 98, 85}
' Get the highest three grades by first sorting
' them in descending order and then taking the
' first three values.
Dim topThreeGrades As IEnumerable(Of Integer) =
grades _
.OrderByDescending(Function(grade) grade) _
.Take(3)
' Display the results.
Dim output As New System.Text.StringBuilder("The top three grades are:" & vbCrLf)
For Each grade As Integer In topThreeGrades
output.AppendLine(grade)
Next
Console.WriteLine(output.ToString())
' This code produces the following output:
'
' The top three grades are:
' 98
' 92
' 85
Remarks
This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator
method directly or by using foreach
in C# or For Each
in Visual Basic.
Take enumerates source
and yields elements until count
elements have been yielded or source
contains no more elements. If count
exceeds the number of elements in source
, all elements of source
are returned.
If count
is less than or equal to zero, source
is not enumerated and an empty IEnumerable<T> is returned.
The Take and Skip methods are functional complements. Given a collection sequence coll
and an integer n
, concatenating the results of coll.Take(n)
and coll.Skip(n)
yields the same sequence as coll
.
In Visual Basic query expression syntax, a Take
clause translates to an invocation of Take.
See also
Applies to
Take<TSource>(IEnumerable<TSource>, Range)
- Source:
- Take.cs
- Source:
- Take.cs
- Source:
- Take.cs
Returns a specified range of contiguous elements from a sequence.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Collections::Generic::IEnumerable<TSource> ^ Take(System::Collections::Generic::IEnumerable<TSource> ^ source, Range range);
public static System.Collections.Generic.IEnumerable<TSource> Take<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Range range);
static member Take : seq<'Source> * Range -> seq<'Source>
<Extension()>
Public Function Take(Of TSource) (source As IEnumerable(Of TSource), range As Range) As IEnumerable(Of TSource)
Type Parameters
- TSource
The type of the elements of source
.
Parameters
- source
- IEnumerable<TSource>
The sequence to return elements from.
- range
- Range
The range of elements to return, which has start and end indexes either from the beginning or the end of the sequence.
Returns
An IEnumerable<T> that contains the specified range of elements from the source
sequence.
Exceptions
source
is null
.
Remarks
This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator
method directly or by using foreach
in C# or For Each
in Visual Basic.
Take enumerates source
and yields elements whose indices belong to the specified range
.