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Hashtable.CopyTo Method

Copies the Hashtable elements to a one-dimensional Array instance at the specified index.

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

public virtual void CopyTo(
	Array array,
	int arrayIndex
)

Parameters

array
Type: System.Array

The one-dimensional Array that is the destination of the DictionaryEntry objects copied from Hashtable. The Array must have zero-based indexing.

arrayIndex
Type: System.Int32

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

Implements

ICollection.CopyTo(Array, Int32)

ExceptionCondition
ArgumentNullException

array is null.

ArgumentOutOfRangeException

arrayIndex is less than zero.

ArgumentException

array is multidimensional.

-or-

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

InvalidCastException

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

The elements are copied to the Array in the same order in which the enumerator iterates through the Hashtable.

To copy only the keys in the Hashtable, use Hashtable.Keys.CopyTo.

To copy only the values in the Hashtable, use Hashtable.Values.CopyTo.

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

The following example shows how to copy the list of keys or the list of values in a Hashtable into a one-dimensional Array.

using System;
using System.Collections;
public class SamplesHashtable  {

   public static void Main()  {

      // Creates and initializes the source Hashtable.
      Hashtable mySourceHT = new Hashtable();
      mySourceHT.Add( "A", "valueA" );
      mySourceHT.Add( "B", "valueB" );

      // Creates and initializes the one-dimensional target Array.
      String[] myTargetArray = new String[15];
      myTargetArray[0] = "The";
      myTargetArray[1] = "quick";
      myTargetArray[2] = "brown";
      myTargetArray[3] = "fox";
      myTargetArray[4] = "jumped";
      myTargetArray[5] = "over";
      myTargetArray[6] = "the";
      myTargetArray[7] = "lazy";
      myTargetArray[8] = "dog";

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

      // Copies the keys in the source Hashtable to the target Hashtable, starting at index 6.
      Console.WriteLine( "After copying the keys, starting at index 6:" );
      mySourceHT.Keys.CopyTo( myTargetArray, 6 );

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

      // Copies the values in the source Hashtable to the target Hashtable, starting at index 6.
      Console.WriteLine( "After copying the values, starting at index 6:" );
      mySourceHT.Values.CopyTo( myTargetArray, 6 );

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

   public static void PrintValues( String[] myArr, char mySeparator )  {
      for ( int i = 0; i < myArr.Length; i++ )
         Console.Write( "{0}{1}", mySeparator, myArr[i] );
      Console.WriteLine();
   }
}
/* 
This code produces the following output.

The target Array contains the following before:
 The quick brown fox jumped over the lazy dog
After copying the keys, starting at index 6:
 The quick brown fox jumped over B A dog
After copying the values, starting at index 6:
 The quick brown fox jumped over valueB valueA dog

*/

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, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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