Rem: Interpolating an Array Element to Reference a Property Name

Q: I'm having problems with the VBScript code in Listing 3. In this script, Array1 is a dynamic array that's populated by using Windows Management Instrumentation (WMI) to retrieve the properties of the Win32_Battery class. When I try to use the contents of this dynamic array to execute a query, I get the error message Error: Object doesn't support this property or method: 'Array1.' I've tried everything I can think of to make this script work but nothing has worked. What am I missing?

A: There are several problems in your script. Before I point out the problems and suggest a possible solution, I should take a minute to clarify what the script is trying to do for the benefit of our readers. In brief, the script is trying to use Array1 as an interpolated variable, as the code at callout C in Listing 3 shows. What does that mean? In the context of scripting languages, to interpolate means to insert the value of a variable into an expression, statement, or string. Let's look at a simple example in Perl, a scripting language that supports interpolated variables. Suppose you have the following code in a script:

my $cn = "cn=tmtowtdi";
my $user = Win32::OLE->
GetObject("LDAP:\\\\$cn,...")
or die;

The snippet begins by assigning the string "cn=tmtowtdi" to the variable named $cn. Next, the code uses the value stored in the $cn variable as part of the connection string used to bind to a user object in Active Directory (AD). Notice how the $cn variable is part of the connection string. That is, the variable is embedded inside the double quoted string; there's no string concatenation or the like being used. When Perl encounters a variable name inside a double quoted string, Perl automatically inserts the variable's value at that point in the string—this is interpolation at work. . . .