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Information.IsReference Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

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

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

Syntax

'Declaration
Public Shared Function IsReference ( _
    Expression As Object _
) As Boolean

public static bool IsReference(
    Object Expression
)

Parameters

Return Value

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

Remarks

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.

Examples

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.

Version Information

Silverlight

Supported in: 5, 4, 3

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.