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Array.GetEnumerator Method

Returns an IEnumerator for the Array.

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

Public Function GetEnumerator As IEnumerator
Dim instance As Array
Dim returnValue As IEnumerator

returnValue = instance.GetEnumerator
public final IEnumerator GetEnumerator ()
public final function GetEnumerator () : IEnumerator

Return Value

An IEnumerator for the Array.

The foreach statement of the C# language (for each in C++, For Each in Visual Basic) hides the complexity of the enumerators. Therefore, using foreach is recommended, instead of directly manipulating the enumerator.

Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.

Initially, the enumerator is positioned before the first element in the collection. Reset also brings the enumerator back to this position. At this position, Current is undefined. Therefore, you must call MoveNext to advance the enumerator to the first element of the collection before reading the value of Current.

Current returns the same object until either MoveNext or Reset is called. MoveNext sets Current to the next element.

If MoveNext passes the end of the collection, the enumerator is positioned after the last element in the collection and MoveNext returns false. When the enumerator is at this position, subsequent calls to MoveNext also return false. If the last call to MoveNext returned false, Current is undefined. To set Current to the first element of the collection again, you can call Reset followed by MoveNext.

An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is irrecoverably invalidated and its behavior is undefined.

The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread safe procedure. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.

This method is an O(1) operation.

The following code example shows how to use GetEnumerator to list the elements of an array.

Imports System

Public Class SamplesArray

   Public Shared Sub Main()

      ' Creates and initializes a new Array.
      Dim myArr(10) As [String]
      myArr(0) = "The"
      myArr(1) = "quick"
      myArr(2) = "brown"
      myArr(3) = "fox"
      myArr(4) = "jumped"
      myArr(5) = "over"
      myArr(6) = "the"
      myArr(7) = "lazy"
      myArr(8) = "dog"

      ' Displays the values of the Array.
      Dim i As Integer = 0
      Dim myEnumerator As System.Collections.IEnumerator = myArr.GetEnumerator()
      Console.WriteLine("The Array contains the following values:")
      While myEnumerator.MoveNext() And Not (myEnumerator.Current Is Nothing)
         Console.WriteLine("[{0}] {1}", i, myEnumerator.Current)
         i += 1
      End While 

   End Sub 'Main

End Class 'SamplesArray 

'This code produces the following output.
'The Array contains the following values:
'[0] The
'[1] quick
'[2] brown
'[3] fox
'[4] jumped
'[5] over
'[6] the
'[7] lazy
'[8] dog

import System.*;

public class SamplesArray
    public static void main(String[] args)
        // Creates and initializes a new Array.
        String myArr[] = new String[10];

        myArr.set_Item(0, "The");
        myArr.set_Item(1, "quick");
        myArr.set_Item(2, "brown");
        myArr.set_Item(3, "fox");
        myArr.set_Item(4, "jumped");
        myArr.set_Item(5, "over");
        myArr.set_Item(6, "the");
        myArr.set_Item(7, "lazy");
        myArr.set_Item(8, "dog");

        // Displays the values of the Array.
        int i = 0;
        System.Collections.IEnumerator myEnumerator = myArr.GetEnumerator();

        Console.WriteLine("The Array contains the following values:");
        while ((myEnumerator.MoveNext() && myEnumerator.get_Current() != null)) {
            Console.WriteLine("[{0}] {1}", System.Convert.ToString(i++), 
    } //main
} //SamplesArray
This code produces the following output.

The Array contains the following values:
[0] The
[1] quick
[2] brown
[3] fox
[4] jumped
[5] over
[6] the
[7] lazy
[8] dog


Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
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