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Is Operator (Visual Basic) 

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Compares two object reference variables.

result = object1 Is object2

Parts

  • result
    Required. Any Boolean value.
  • object1
    Required. Any Object name.
  • object2
    Required. Any Object name.

Remarks

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

Is can also be used with the TypeOf keyword to make a TypeOf...Is expression, which tests whether an object variable is compatible with a data type.

Example

The following example uses the Is operator to compare pairs of object references. The results are assigned to a Boolean value representing whether the two objects are identical.

Dim myObject As New Object
Dim otherObject As New Object
Dim yourObject, thisObject, thatObject As Object
Dim myCheck As Boolean
yourObject = myObject
thisObject = myObject
thatObject = otherObject
' The following statement sets myCheck to True.
myCheck = yourObject Is thisObject
' The following statement sets myCheck to False.
myCheck = thatObject Is thisObject
' The following statement sets myCheck to False.
myCheck = myObject Is thatObject
thatObject = myObject
' The following statement sets myCheck to True.
myCheck = thisObject Is thatObject

As the preceding example demonstrates, you can use the Is operator to test both early bound and late bound objects.

See Also

Reference

TypeOf Operator (Visual Basic)
IsNot Operator
Operator Precedence in Visual Basic
Operators Listed by Functionality

Concepts

Comparison Operators in Visual Basic
Operators and Expressions in Visual Basic