Array.CreateInstance Method (Type, Int32)

 

Creates a one-dimensional Array of the specified Type and length, with zero-based indexing.

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

Public Shared Function CreateInstance (
	elementType As Type,
	length As Integer
) As Array

Parameters

elementType
Type: System.Type

The Type of the Array to create.

length
Type: System.Int32

The size of the Array to create.

Return Value

Type: System.Array

A new one-dimensional Array of the specified Type with the specified length, using zero-based indexing.

Exception Condition
ArgumentNullException

elementType is null.

ArgumentException

elementType is not a valid Type.

NotSupportedException

elementType is not supported. For example, Void is not supported.

-or-

elementType is an open generic type.

ArgumentOutOfRangeException

length is less than zero.

Unlike most classes, Array provides the CreateInstance method, instead of public constructors, to allow for late bound access.

Reference-type elements are initialized to null. Value-type elements are initialized to zero.

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

The following code example shows how to create and initialize a one-dimensional Array.

Imports System
Imports Microsoft.VisualBasic

Public Class SamplesArray    

    Public Shared Sub Main()

        ' Creates and initializes a one-dimensional Array of type Int32.
        Dim my1DArray As Array = Array.CreateInstance(GetType(Int32), 5)
        Dim i As Integer
        For i = my1DArray.GetLowerBound(0) To my1DArray.GetUpperBound(0)
            my1DArray.SetValue(i + 1, i)
        Next i 
        ' Displays the values of the Array.
        Console.WriteLine("The one-dimensional Array contains the " _
           + "following values:")
        PrintValues(my1DArray)

    End Sub

    Public Shared Sub PrintValues(myArr As Array)
        Dim myEnumerator As System.Collections.IEnumerator = _
           myArr.GetEnumerator()
        Dim i As Integer = 0
        Dim cols As Integer = myArr.GetLength((myArr.Rank - 1))
        While myEnumerator.MoveNext()
            If i < cols Then
                i += 1
            Else
                Console.WriteLine()
                i = 1
            End If
            Console.Write(ControlChars.Tab + "{0}", myEnumerator.Current)
        End While
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' The one-dimensional Array contains the following values:
'     1    2    3    4    5 

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Return to top
Show: