VB.NET Convert ArrayList to Array

Convert an ArrayList to an array. Invoke the ToArray Function.

Convert ArrayList, Array. An ArrayList can be converted to an array. This is possible with the ToArray Function. With it we get an Object array from an ArrayList. ToArray is useful—it is not the same as the ToArray extension from System.Linq.

To start, we create an ArrayList and populate it with three String references. Please notice how all the elements in the ArrayList are of type String. This is important—when we call ToArray, we get an Object array, not a String array.

However: When we loop through the Object array, we can cast each element to a String.

Object Array

Note: We can not directly cast the array to a String(). This exception is reported.

Quote: Unhandled Exception: System.InvalidCastException: Unable to cast object of type 'System.Object[]' to type 'System.String[]'.

VB.NET program that converts ArrayList to Object array Module Module1 Sub Main() ' Create ArrayList. Dim list As ArrayList = New ArrayList() list.Add("Dot") list.Add("Net") list.Add("Perls") ' Get array of objects. Dim array() As Object = list.ToArray() For Each element In array ' Cast object to string. Dim value As String = element Console.WriteLine(value) Next End Sub End Module Output Dot Net Perls

Discussion. The ArrayList makes converting your collection to an array more difficult. If you use the List type, you can convert to a typed array such as String(). This results in much clearer code. I recommend the List type in almost all programs.List

Summary. We used the ToArray function on the ArrayList type to convert an ArrayList to an Object() array. We looked at the exception that is thrown when you try to cast the result array, and also pointed out the superior List type.ArrayListArray
Dot Net Perls
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