IsReference Method

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
public static boolean IsReference (
	Object Expression
public static function IsReference (
	Expression : Object
) : boolean



Required. Object expression.

Return Value

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

For more detailed information, see the Visual Basic topic IsReference Function.

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.

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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