IsNot Operator (Visual Basic)
Compares two object reference variables.
Syntax
result = object1 IsNot object2
Parts
result
Required. A
Boolean
value.object1
Required. Any
Object
variable or expression.object2
Required. Any
Object
variable or expression.
Remarks
The IsNot
operator determines if two object references refer to different objects. However, it doesn't perform value comparisons. If object1
and object2
both refer to the exact same object instance, result
is False
; if they don't, 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.
Example
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.")
Use TypeOf operator with IsNot operator
Starting with Visual Basic 14, you can use the TypeOf
operator with the IsNot
operator to test whether an object is not compatible with a data type. For example:
If TypeOf sender IsNot Button Then