Enumerable.Prepend(IEnumerable<TSource>, TSource) Enumerable.Prepend(IEnumerable<TSource>, TSource) Enumerable.Prepend(IEnumerable<TSource>, TSource) Enumerable.Prepend(IEnumerable<TSource>, TSource) Method

Definición

Agrega un valor al principio de la secuencia.Adds a value to the beginning of the sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::IEnumerable<TSource> ^ Prepend(System::Collections::Generic::IEnumerable<TSource> ^ source, TSource element);
public static System.Collections.Generic.IEnumerable<TSource> Prepend<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, TSource element);
static member Prepend : seq<'Source> * 'Source -> seq<'Source>
<Extension()>
Public Function Prepend(Of TSource) (source As IEnumerable(Of TSource), element As TSource) As IEnumerable(Of TSource)

Parámetros de tipo

TSource

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

Parámetros

source
IEnumerable<TSource>

Secuencia de valores.A sequence of values.

element
TSource TSource TSource TSource

Valor para anteponer a source.The value to prepend to source.

Devoluciones

IEnumerable<TSource>

Nueva secuencia que comienza con element.A new sequence that begins with element.

Excepciones

Ejemplos

En el ejemplo de código siguiente se muestra Prepend cómo usar para anteponer un valor al principio de la secuencia.The following code example demonstrates how to use Prepend to prepend a value to the beginning of the sequence.

// Creating a list of numbers
List<int> numbers = new List<int> { 1, 2, 3, 4 };

// Trying to prepend any value of the same type
numbers.Prepend(0);

// It doesn't work because the original list has not been changed
Console.WriteLine(string.Join(", ", numbers));

// It works now because we are using a changed copy of the original list
Console.WriteLine(string.Join(", ", numbers.Prepend(0)));

// If you prefer, you can create a new list explicitly
List<int> newNumbers = numbers.Prepend(0).ToList();

// And then write to the console output
Console.WriteLine(string.Join(", ", newNumbers));

// This code produces the following output:
//
// 1, 2, 3, 4
// 0, 1, 2, 3, 4
// 0, 1, 2, 3, 4
' Creating a list of numbers
Dim numbers As New List(Of Integer)(New Integer() {1, 2, 3, 4})

' Trying to prepend any value of the same type
numbers.Prepend(0)

' It doesn't work because the original list has not been changed
Console.WriteLine(String.Join(", ", numbers))

' It works now because we are using a changed copy of the original list
Console.WriteLine(String.Join(", ", numbers.Prepend(0)))

' If you prefer, you can create a new list explicitly
Dim newNumbers As List(Of Integer) = numbers.Prepend(0).ToList

' And then write to the console output
Console.WriteLine(String.Join(", ", newNumbers))

' This code produces the following output:
'
' 1, 2, 3, 4
' 0, 1, 2, 3, 4
' 0, 1, 2, 3, 4

Comentarios

Nota

Este método no modifica los elementos de la colección.This method does not modify the elements of the collection. En su lugar, crea una copia de la colección con el nuevo elemento.Instead, it creates a copy of the collection with the new element.

Se aplica a