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List.CopyTo Method (T[], Int32)

Copies the entire List to a compatible one-dimensional array, starting at the specified index of the target array.

Namespace: System.Collections.Generic
Assembly: mscorlib (in mscorlib.dll)

Public Sub CopyTo ( _
	array As T(), _
	arrayIndex As Integer _
Dim instance As List(Of T)
Dim array As T()
Dim arrayIndex As Integer

instance.CopyTo(array, arrayIndex)
public final void CopyTo (
	T[] array, 
	int arrayIndex
public final function CopyTo (
	array : T[], 
	arrayIndex : int
Not applicable.



The one-dimensional Array that is the destination of the elements copied from List. The Array must have zero-based indexing.


The zero-based index in array at which copying begins.

Exception typeCondition


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


arrayIndex is less than 0.


arrayIndex is equal to or greater than the length of array.


The number of elements in the source List is greater than the available space from arrayIndex to the end of the destination array.

This method uses System.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.

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 strings is created and populated with 5 strings. An empty string array of 15 elements is created, and the CopyTo(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(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,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.

Imports System
Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)


        For Each dinosaur As String In dinosaurs

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

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

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

    End Sub
End Class

' This code example produces the following output:
'Contents of the array:

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

.NET Compact Framework

Supported in: 2.0

XNA Framework

Supported in: 1.0