Errata

The statement, "...strPrefix is an optional string that instructs WSH to trap the
object's events (if it has any) and to fire event handlers whose names begin with
strPrefix followed by an underscore, followed by the event name." is incorrect. In
fact, no underscore is used; the strPrefix and the event name must be directly
concatenated.

I recently reported an erratum in the description of the CreateObject method on page
136. This concerns the incorrect statement that an underscore must be used to join
the strPrefix with the event name. I now realize that this same error applies here
to the description of GetObject.

The decription indicates that you can use an integer index to access one of the
environment variable name/value pairs. This is not correct, you can only access
a value via the Item property using the varible's name, for example "PATH".
[This also true for default access].

In order to iterate through the list of name/value pairs you need to "enumerate"
the object created with the:

Set wsh = WScript.CreateObject("WScript.Shell")

command. This is [of course] done as follows in vbScript:

for sPair in wsh
'do something with this name/value pair
next

It would be valuable to correct the above and mention how to iterate. As a new
user I spent a lot of time figuring this out.

The second bullet under CSng Function, Rules at a Glance, now reads
If the value of expression is outside the range of the double
datatype, an overflow error is generated.

It should read:

If the value of expression is outside the range of the single
datatype, an overflow error is generated.

Book states "If the variant passed to IsEmpy has been initialized, True is returned;
otherwise, IsEmpty returns False."

In my experience, True is returned if the variant is uninitialized, so an If IsEmpty
statement will execute if the variant is empty.

The 2nd line now reads:

The first character in the search string is at position 1

It should read:

The first character in the sentence is at position 0 (zero)

cfr: http://msdn.microsoft.com/library/default.asp?url=/library/en-
us/script56/html/vsprofirstindex.asp

The FirstIndex property uses a zero-based offset from the beginning of the search
string. In other words, the first character in the string is identified as character
zero (0).

The paragraph reads:

"Once you enable error handling with the On Error Resume Next statement, VBScript
provides no means to disable it. This contrasts with VBA, in which the On Error Goto
0 statement disables error handling."

This incorrect. VBScript does support the On Error Goto 0 statement to disable error
handling.

The description of the "arrayname" argument to UBound asserts that it must be the
name of an array. This is not true! All it needs to be is an array. It may be
referenced by name or in some other way. For example, "UBound(Array(1,2,3))" works
just fine. (This example is, of course, not a useful one!)

"vbNullString" is defined as equating to the value "Zero Length String". This is
seriously incorrect. Microsoft's own documentation states that, it is "Not the same
as a zero-length string (""); used for calling external procedures." In fact it is a
NULL pointer.