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Information.IsReference Method

Returns a Boolean value indicating whether an expression evaluates to a reference type.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public static bool IsReference(
	Object Expression
)

Parameters

Expression
Type: System.Object
Required. Object expression.

Return Value

Type: System.Boolean
Returns a Boolean value indicating whether an expression evaluates to a reference type.

IsReference returns True if Expression represents a reference type, such as a class instance, a String type, or an array of any type; otherwise, it returns False.

A reference type contains a pointer to data stored elsewhere in memory. A value type contains its own data.

This example uses the IsReference function to check if several variables refer to reference types.


Dim testArray(3) As Boolean
Dim testString As String = "Test string"
Dim testObject As Object = New Object()
Dim testNumber As Integer = 12
testArray(0) = IsReference(testArray)
testArray(1) = IsReference(testString)
testArray(2) = IsReference(testObject)
testArray(3) = IsReference(testNumber)


In the preceding example, the first three calls to IsReference return True. The last call returns False, because Integer is a value type, not a reference type.

.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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