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Type.IsValueType Property

Updated: October 2008

Gets a value indicating whether the Type is a value type.

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

'Declaration
Public ReadOnly Property IsValueType As Boolean
'Usage
Dim instance As Type 
Dim value As Boolean 

value = instance.IsValueType

Property Value

Type: System.Boolean
true if the Type is a value type; otherwise, false.

Implements

_Type.IsValueType

Value types are types that are represented as sequences of bits; value types are not classes or interfaces. Value types are referred to as "structs" in some programming languages. Enums are a special case of value types.

This property returns false for the ValueType class, because ValueType is not a value type itself. It is the base class for all value types, and therefore any value type can be assigned to it. This would not be possible if ValueType itself was a value type. Value types are boxed when they are assigned to a field of type ValueType.

This property returns true for enumerations, but not for the Enum type itself. For an example that demonstrates this behavior, see IsEnum.

This property is read-only.

The following example creates a variable of type MyEnum, checks for the IsValueType property, and displays the result.

Imports System
Imports Microsoft.VisualBasic
Namespace SystemType
    Public Class [MyClass]

        ' Declare an enum type. 
        Enum MyEnum
            One
            Two
        End Enum 'MyEnum

        Public Overloads Shared Sub Main()
            Try 
                Dim myBool As Boolean = False 
                Dim myTestEnum As MyEnum = MyEnum.One
                ' Get the type of myTestEnum. 
                Dim myType As Type = myTestEnum.GetType()
                ' Get the IsValueType property of the myTestEnum variable.
                myBool = myType.IsValueType
                Console.WriteLine(ControlChars.Cr + "Is {0} a value type? {1}.", myType.FullName, myBool.ToString())
            Catch e As Exception
                Console.WriteLine(ControlChars.Cr + "An exception occurred: {0}", e.Message.ToString())
            End Try 
        End Sub 'Main
    End Class '[MyClass] 
End Namespace 'SystemType

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

Date

History

Reason

October 2008

Explained why false is returned for ValueType.

Content bug fix.

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