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List<T>::CopyTo Method (array<T>, Int32)

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

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

public:
virtual void CopyTo(
	array<T>^ array, 
	int arrayIndex
) sealed

Parameters

array
Type: array<T>

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

arrayIndex
Type: System::Int32

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

Implements

ICollection<T>::CopyTo(array<T>, Int32)

ExceptionCondition
ArgumentNullException

array is nullptr.

ArgumentOutOfRangeException

arrayIndex is less than 0.

ArgumentException

The number of elements in the source List<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<T>.

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

The following example demonstrates all three overloads of the CopyTo method. A List<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.

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
 */

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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