IsObject
Returns a Boolean indicating whether an identifier represents an object variable.
Syntax: IsObject( identifier )
- identifier
- required A variable name.
IsObject is useful only for determining whether a Variant holds VarType vbObject. This is the case if the Variant actually references — or once referenced — an object, or if it contains Nothing.
IsObject returns True if identifier is a variable declared with Object type or any valid class type, or if identifier is a Variant of VarType vbObject, or a user-defined object; otherwise, it returns False.
IsObject returns True even if the variable has been set to Nothing. Use error trapping to be sure that an object reference is valid before dereferencing it.
Note
twinBASIC also exposes a generic form, IsObject(Of T), which is useful for compile-time verification of generic type specifiers. The non-generic call uses special internal bindings and so may not behave like a regular function.
Example
This example uses IsObject to determine whether an identifier represents an object variable. MyObject and YourObject are object variables of the same type, used here for illustration.
Dim MyInt As Integer ' Declare variables.
Dim YourObject As Variant, MyCheck As Boolean
Dim MyObject As Object
Set YourObject = MyObject ' Assign an object reference.
MyCheck = IsObject(YourObject) ' Returns True.
MyCheck = IsObject(MyInt) ' Returns False.
MyCheck = IsObject(Nothing) ' Returns True.
MyCheck = IsObject(Empty) ' Returns False.
MyCheck = IsObject(Null) ' Returns False.