Enumerable.Take<TSource>(IEnumerable<TSource>, Int32) Method

Definition

Devuelve un número especificado de elementos contiguos desde el principio de una secuencia.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

Tipo de los elementos de source.The type of the elements of source.

Parameters

source
IEnumerable<TSource>

Secuencia cuyos elementos se van a devolver.The sequence to return elements from.

count
Int32

Número de elementos que se van a devolver.The number of elements to return.

Returns

IEnumerable<TSource>

IEnumerable<T> que contiene el número especificado de elementos desde el principio de la secuencia de entrada.An IEnumerable<T> that contains the specified number of elements from the start of the input sequence.

Exceptions

source es null.source is null.

Examples

En el ejemplo de código siguiente se muestra cómo usar Take para devolver elementos desde el principio de una secuencia.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

Este método se implementa mediante la ejecución aplazada.This method is implemented by using deferred execution. El valor devuelto inmediato es un objeto que almacena toda la información necesaria para realizar la acción.The immediate return value is an object that stores all the information that is required to perform the action. La consulta representada por este método no se ejecuta hasta que el objeto se enumera llamando a su método GetEnumerator directamente o utilizando foreach en Visual C# o For Each en Visual Basic.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 Visual C# or For Each in Visual Basic.

Take enumera source y produce los elementos hasta que se hayan producido count elementos o source no contengan más elementos.Take enumerates source and yields elements until count elements have been yielded or source contains no more elements. Si count supera el número de elementos de source, se devuelven todos los elementos de source.If count exceeds the number of elements in source, all elements of source are returned.

Si count es menor o igual que cero, source no se enumera y se devuelve una IEnumerable<T> vacía.If count is less than or equal to zero, source is not enumerated and an empty IEnumerable<T> is returned.

Los métodos Take y Skip son complementos funcionales.The Take and Skip methods are functional complements. Dada una secuencia coll y un entero n, la concatenación de los resultados de coll.Take(n) y coll.Skip(n) produce la misma secuencia que coll.Given a sequence coll and an integer n, concatenating the results of coll.Take(n) and coll.Skip(n) yields the same sequence as coll.

En Visual Basic sintaxis de las expresiones de consulta, una cláusula de Take se convierte en una invocación de Take.In Visual Basic query expression syntax, a Take clause translates to an invocation of Take.

Applies to

See also