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I have a "problem" with a vbscript. I check if a cd is loaded with this piece of code: 

On Error Resume Next
Computer = "."
Set OutFile = CreateObject("WScript.Shell")
Const ForAppending = 2
Set FileSystem = CreateObject("Scripting.FileSystemObject")
Set WMIService = GetObject("winmgmts:\\" & Computer & "\root\cimv2")
Set Items = WMIService.ExecQuery("Select * from Win32_CDROMDrive WHERE DRIVE = 'F:'",,48)
For Each SubItems in Items
WScript.Echo "DRIVE: "&SubItems.MediaLoaded
Next

It returns "DRIVE: False"

But if I change the line that prints the output for:

WScript.Echo SubItems.MediaLoaded

Returns -1

Someone knows how I could get "DRIVE:-1" ?

I solved with WScript.Echo "DRIVE: "&cint(SubItems.MediaLoaded) thanks to madzone

share|improve this question
    
WScript.Echo "DRIVE: " & str(SubItems.MediaLoaded) –  matzone May 24 '13 at 16:32
    
Thank you for the response, it didn't help, but it gives me some clues to solve it. I do it with cint(SubItems.MediaLoaded) –  user1675150 May 24 '13 at 16:43
    
good luck ..... –  matzone May 24 '13 at 16:54

3 Answers 3

up vote 1 down vote

I'm not good in English and I think Ekkehard Horner explanations is better than mine. What I know is that string concatenation turn Boolean data type in their literal form.

WScript.Echo "" & False, 0, False  '>> False 0 0
WScript.Echo "" & True, -1, True   '>> True -1 -1
WScript.Echo 0 = False, 0 = True   '>> -1 0
WScript.Echo -1 = False, -1 = True '>> 0 -1
share|improve this answer
    
correct/+1, but I'd prefer '& displays Booleans in their literal form' over 'turns'. Nothing is changed. –  Ekkehard.Horner May 24 '13 at 21:17
    
@Ekkehard.Horner agreed, you're right about 'turns'. –  seeker May 25 '13 at 11:27
up vote 0 down vote

Use the CInt function to convert the string back to an integer.

WScript.Echo "Drive: " & CInt(SubItems.MediaLoaded)
share|improve this answer
    
There is no string involved: -0.49 –  Ekkehard.Horner May 24 '13 at 18:09
up vote 0 down vote

According to the docs, .MediaLoaded's type is boolean

MediaLoaded

Data type: boolean
Access type: Read-only

If True, a CD-ROM is in the drive.

The concatenation operator & handles VBScript's (sub) types correctly:

>> bTrue = True
>> bFalse = False
>> n0 = 0
>> nM1 = -1
>> WScript.Echo "&" & bTrue & bFalse & n0 & nM1
>>
&TrueFalse0-1

The internal stringifier component of WScript.Echo does not:

>> WScript.Echo ".Echo ,", bTrue, bFalse, n0, nM1
>>
.Echo , -1 0 0 -1

Probably the & operator calls CStr() internally:

>> WScript.Echo "CStr() ,", CStr(bTrue), CStr(bFalse), CStr(n0), CStr(nM1)
>>
CStr() , True False 0 -1

The Join function is industrious too:

>> WScript.Echo "Join", Join(Array(bTrue, bFalse, n0, nM1))
>>
Join True False 0 -1

Of course you are entitled to have your output look like

DRIVE: 0
DRIVE: -1

instead of:

MediaLoaded: False
MediaLoaded: True

but it's not fair to accuse the hardworking & of changing anything.

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