CopyTo Method (T[], Int32)
.NET Framework Class Library
List<(Of <(T>)>)..::.CopyTo Method (array<T>[]()[], Int32)

Copies the entire List<(Of <(T>)>) to a compatible one-dimensional array, starting at the specified index of the target array.

Namespace:  System.Collections.Generic
Assembly:  mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
Public Sub CopyTo ( _
    array As T(), _
    arrayIndex As Integer _
)
Visual Basic (Usage)
Dim instance As List
Dim array As T()
Dim arrayIndex As Integer

instance.CopyTo(array, arrayIndex)
C#
public void CopyTo(
    T[] array,
    int arrayIndex
)
Visual C++
public:
virtual void CopyTo(
    array<T>^ array, 
    int arrayIndex
) sealed
JScript
public final function CopyTo(
    array : T[], 
    arrayIndex : int
)

Parameters

array
Type: array<T>[]()[]
The one-dimensional Array that is the destination of the elements copied from List<(Of <(T>)>). The Array must have zero-based indexing.
arrayIndex
Type: System..::.Int32
The zero-based index in array at which copying begins.

Implements

ICollection<(Of <(T>)>)..::.CopyTo(array<T>[]()[], Int32)
ExceptionCondition
ArgumentNullException

array is nullNothingnullptra null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

arrayIndex is less than 0.

ArgumentException

The number of elements in the source List<(Of <(T>)>) is greater than the available space from arrayIndex to the end of the destination array.

This method uses Array..::.Copy to copy the elements.

The elements are copied to the Array in the same order in which the enumerator iterates through the List<(Of <(T>)>).

This method is an O(n) operation, where n is Count.

The following code example demonstrates all three overloads of the CopyTo method. A List<(Of <(T>)>) of strings is created and populated with 5 strings. An empty string array of 15 elements is created, and the CopyTo(array<T>[]()[]) method overload is used to copy all the elements of the list to the array beginning at the first element of the array. The CopyTo(array<T>[]()[], Int32) method overload is used to copy all the elements of the list to the array beginning at array index 6 (leaving index 5 empty). Finally, the CopyTo(Int32, array<T>[]()[], Int32, Int32) method overload is used to copy 3 elements from the list, beginning with index 2, to the array beginning at array index 12 (leaving index 11 empty). The contents of the array are then displayed.

Visual Basic
Imports System
Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)

        dinosaurs.Add("Tyrannosaurus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Brachiosaurus")
        dinosaurs.Add("Compsognathus")

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        ' Declare an array with 15 elements (0 through 14).
        Dim array(14) As String

        dinosaurs.CopyTo(array)
        dinosaurs.CopyTo(array, 6)
        dinosaurs.CopyTo(2, array, 12, 3)

        Console.WriteLine(vbLf & "Contents of the array:")
        For Each dinosaur As String In array
            Console.WriteLine(dinosaur)
        Next

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Compsognathus
'
'Contents of the array:
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Compsognathus
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Compsognathus
'
'Mamenchisaurus
'Brachiosaurus
'Compsognathus
C#
using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();

        dinosaurs.Add("Tyrannosaurus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Brachiosaurus");
        dinosaurs.Add("Compsognathus");

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }

        // Declare an array with 15 elements.
        string[] array = new string[15];

        dinosaurs.CopyTo(array);
        dinosaurs.CopyTo(array, 6);
        dinosaurs.CopyTo(2, array, 12, 3);

        Console.WriteLine("\nContents of the array:");
        foreach(string dinosaur in array)
        {
            Console.WriteLine(dinosaur);
        }
    }
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Compsognathus

Contents of the array:
Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Compsognathus

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Compsognathus

Mamenchisaurus
Brachiosaurus
Compsognathus
 */
Visual C++
using namespace System;
using namespace System::Collections::Generic;

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();

    dinosaurs->Add("Tyrannosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Brachiosaurus");
    dinosaurs->Add("Compsognathus");

    Console::WriteLine();
    for each(String^ dinosaurs in dinosaurs )
    {
        Console::WriteLine(dinosaurs);
    }

    // Create an array of 15 strings.
    array<String^>^ arr = gcnew array<String^>(15);

    dinosaurs->CopyTo(arr);
    dinosaurs->CopyTo(arr, 6);
    dinosaurs->CopyTo(2, arr, 12, 3);

    Console::WriteLine("\nContents of the array:");
    for each(String^ dinosaurs in arr )
    {
        Console::WriteLine(dinosaurs);
    }
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

IndexOf("Tyrannosaurus"): 0

IndexOf("Tyrannosaurus", 3): 5

IndexOf("Tyrannosaurus", 2, 2): -1
 */

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0
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