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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)

'Declaration
Public Overridable Sub CopyTo ( _
	array As Array, _
	arrayIndex As Integer _
)

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 Nothing.

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.


Imports System
Imports System.Collections

Public Class SamplesHashtable

    Public Shared Sub Main()

        ' Creates and initializes the source Hashtable.
        Dim mySourceHT As New Hashtable()
        mySourceHT.Add("A", "valueA")
        mySourceHT.Add("B", "valueB")

        ' Creates and initializes the one-dimensional target Array.
        Dim myTargetArray(14) As String
        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, " "c)

        ' 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, " "c)

        ' 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, " "c)

    End Sub 'Main

    Public Shared Sub PrintValues(myArr() As String, mySeparator As Char)
        Dim i As Integer
        For i = 0 To myArr.Length - 1
            Console.Write("{0}{1}", mySeparator, myArr(i))
        Next i
        Console.WriteLine()
    End Sub 'PrintValues

End Class 'SamplesHashtable


' 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



.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.

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