VBScript in a Nutshell, 2nd Edition

Name

IsObject Function

Syntax

IsObject(varname)

varname

Use: Required

Data Type: Any

Name of the variable to be evaluated.

Return Value

Boolean (True or False).

Description

Indicates whether a variable contains a reference to an object—in other words, if it’s an object variable.

Rules at a Glance

If the variable passed to IsObject references or has referenced an object, even if its value is Nothing, True is returned; otherwise, IsObject returns False.

Programming Tips and Gotchas

• IsObject doesn’t validate the reference being held by an object variable; it simply determines whether the variable is an object. To ensure that an object reference is valid, you can use the syntax Is Nothing, as shown in this code snippet:

  If objVar Is Nothing Then
  ...
  End if

• IsObject is simply a “convenience” function that is roughly equivalent to the following user-defined function:

  Public Function IsObject(varObj)
  
  If VarType(varObj) = vbObject Then
     IsObject = True
  Else
     IsObject = False
  End If
  
  End Function