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Array.CopyTo Method (Array, Int32)

Copies all the elements of the current one-dimensional Array to the specified one-dimensional Array starting at the specified destination Array index. The index is specified as a 32-bit integer.

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

public void CopyTo(
	Array array,
	int index


Type: System.Array
The one-dimensional Array that is the destination of the elements copied from the current Array.
Type: System.Int32
A 32-bit integer that represents the index in array at which copying begins.


ICollection.CopyTo(Array, Int32)


array is null.


index is less than the lower bound of array.


array is multidimensional.


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


The type of the source Array cannot be cast automatically to the type of the destination array.


The source Array is multidimensional.


At least one element in the source Array cannot be cast to the type of destination array.

This method supports the System.Collections.ICollection interface. If implementing System.Collections.ICollection is not explicitly required, use Copy to avoid an extra indirection.

If this method throws an exception while copying, the state of array is undefined.

This method is an O(n) operation, where n is Length. It performs a shallow copy only.

The following code example shows how to copy an Array to another Array.

using System;
public class SamplesArray  {

   public static void Main()  {

      // Creates and initializes two new Arrays.
      Array mySourceArray=Array.CreateInstance( typeof(String), 6 );
      mySourceArray.SetValue( "three", 0 );
      mySourceArray.SetValue( "napping", 1 );
      mySourceArray.SetValue( "cats", 2 );
      mySourceArray.SetValue( "in", 3 );
      mySourceArray.SetValue( "the", 4 );
      mySourceArray.SetValue( "barn", 5 );
      Array myTargetArray=Array.CreateInstance( typeof(String), 15 );
      myTargetArray.SetValue( "The", 0 );
      myTargetArray.SetValue( "quick", 1 );
      myTargetArray.SetValue( "brown", 2 );
      myTargetArray.SetValue( "fox", 3 );
      myTargetArray.SetValue( "jumps", 4 );
      myTargetArray.SetValue( "over", 5 );
      myTargetArray.SetValue( "the", 6 );
      myTargetArray.SetValue( "lazy", 7 );
      myTargetArray.SetValue( "dog", 8 );

      // Displays the values of the Array.
      Console.WriteLine( "The target Array contains the following (before and after copying):" );
      PrintValues( myTargetArray, ' ' );

      // Copies the source Array to the target Array, starting at index 6.
      mySourceArray.CopyTo( myTargetArray, 6 );

      // Displays the values of the Array.
      PrintValues( myTargetArray, ' ' );

   public static void PrintValues( Array myArr, char mySeparator )  {
      System.Collections.IEnumerator myEnumerator = myArr.GetEnumerator();
      int i = 0;
      int cols = myArr.GetLength( myArr.Rank - 1 );
      while ( myEnumerator.MoveNext() )  {
         if ( i < cols )  {
         } else  {
            i = 1;
         Console.Write( "{0}{1}", mySeparator, myEnumerator.Current );
This code produces the following output.

 The target Array contains the following (before and after copying):
 The quick brown fox jumps over the lazy dog      
 The quick brown fox jumps over three napping cats in the barn

The following code example shows how to copy an Array to another Array with a nonzero lower bound. Note that the entire source Array is copied, including empty elements that overwrite existing elements in the target Array.

public class SamplesArray2{

   public static void Main()  {
      // Creates and initializes the source Array.
      Array myArrayZero=Array.CreateInstance( typeof(String), 3 );
      myArrayZero.SetValue( "zero", 0 );
      myArrayZero.SetValue( "one", 1 );

      // Displays the source Array.
      Console.WriteLine( "The array with lower bound=0 contains:" );
      PrintIndexAndValues( myArrayZero );

      // Creates and initializes the target Array.
      int[] myArrLen = { 4 };
      int[] myArrLow = { 2 };
      Array myArrayTwo=Array.CreateInstance( typeof(String), myArrLen, myArrLow );
      myArrayTwo.SetValue( "two", 2 );
      myArrayTwo.SetValue( "three", 3 );
      myArrayTwo.SetValue( "four", 4 );
      myArrayTwo.SetValue( "five", 5 );

      // Displays the target Array.
      Console.WriteLine( "The array with lower bound=2 contains:" );
      PrintIndexAndValues( myArrayTwo );

      // Copies from the array with lower bound=0 to the array with lower bound=2.
      myArrayZero.CopyTo( myArrayTwo, 3 );

      // Displays the modified target Array.
      Console.WriteLine( "\nAfter copying to the target array from index 3:" );
      PrintIndexAndValues( myArrayTwo );

   public static void PrintIndexAndValues( Array myArray )  {
      for ( int i = myArray.GetLowerBound(0); i <= myArray.GetUpperBound(0); i++ )
         Console.WriteLine( "\t[{0}]:\t{1}", i, myArray.GetValue( i ) );
This code produces the following output.

The array with lower bound=0 contains:
    [0]:    zero
    [1]:    one
The array with lower bound=2 contains:
    [2]:    two
    [3]:    three
    [4]:    four
    [5]:    five

After copying to the target array from index 3:
    [2]:    two
    [3]:    zero
    [4]:    one

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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