IsNot Operator (Visual Basic)

 

Updated: July 20, 2015

For the latest documentation on Visual Studio 2017, see Visual Studio 2017 Documentation.

Compares two object reference variables.

  
result = object1 IsNot object2  

result
Required. A Boolean value.

object1
Required. Any Object variable or expression.

object2
Required. Any Object variable or expression.

The IsNot operator determines if two object references refer to different objects. However, it does not perform value comparisons. If object1 and object2 both refer to the exact same object instance, result is False; if they do not, result is True.

IsNot is the opposite of the Is operator. The advantage of IsNot is that you can avoid awkward syntax with Not and Is, which can be difficult to read.

You can use the Is and IsNot operators to test both early-bound and late-bound objects.

System_CAPS_ICON_note.jpg Note

The IsNot operator cannot be used to compare expressions returned from the TypeOf operator. Instead, you must use the Not and Is operators.

The following code example uses both the Is operator and the IsNot operator to accomplish the same comparison.

        Dim o1, o2 As New Object
        If Not o1 Is o2 Then MsgBox("o1 and o2 do not refer to the same instance.")
        If o1 IsNot o2 Then MsgBox("o1 and o2 do not refer to the same instance.")

Is Operator
TypeOf Operator
Operator Precedence in Visual Basic
How to: Test Whether Two Objects Are the Same

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