Clarity on VBS code handling

[reyreyreyes]

Hi all

I'm brand new to VBScript, but came across this forum during my search for help on finding a way to copy a file automatically.

Anyway, I found that (thanks to people here), but I'm curious about one thing. Why is it, in this portion of code:

for each g in ofolder.files
    if strcomp(left(g.name,2),"Le",1)=0 then
        objFso.copyfile g.path,flDestination,true

Can I replace the 'g' with 'f' or any other letter and it still work? How does it know that when I'm saying 'for each g' that I mean each file? Does it just assume whatever letter/word is there is a nickname for each file within the collection I'm referring to?

Sorry if this is a stupid question, but I don't get it, unless what I said above is right!

Thank you!

 

[guitarzan]

In that statement, g is a variable name that gets replaced with each item in the "ofolder.files" collection. You can use any name you want for a variable, like g, or f, or ThisFileName, or anything that isn't a reserved word in vbscript.

http://ss64.com/vb/foreach.html

>How does it know that when I'm saying 'for each g' that I mean each file?

Because presumably, ofolder is a "FileSystem Object" folder object. Set something like this:

Set fso = CreateObject("Scripting.FileSystemObject")
Set ofolder = fso.GetFolder("C:\Data\MyFolder")

FSO Folder objects contain a "Files" property (among many others), which is a collection of file objects in that folder

 

[reyreyreyes]

Thanks guitarzan - great points that I can understand.

I think this also revealed my lack of knowledge with 'for each' because I was still wondering (and kind of still am) why you can just throw a variable after 'For each...' without having previously declared it in the normal 'Dim' fashion. Is that because the data-type would be a variant, and undeclared data-types, by default, are variant?

Thanks again!

 

[guitarzan]

You SHOULD declare all variables with a Dim statement for a variety of reasons, but unless you use the line Option Explicit as the first line of your script, you are not FORCED to declare it. I definitely recommend using Option Explicit. If you use it, and you have a typo in a variable name, you will get a "Variable is undefined" error (and you have the ability to correct it). If you don't use Option Explicit, your code will think the misspelled variable is simply a new variable, giving you unexpected results.

 

[guitarzan]

Also, all variables in VBScript are variants... depending on the value they have, they will be one of a number of [link

http://www.herongyang.com/VBScript/Data-Type-Variant-Subtype.html

]Subtypes[/url], which if needed, can be converted to other subtypes using one of the conversion functions, such as CInt(), CCur(), CDbl() (see [link itknowledgeexchange.techtarget.com/vbscript-systems-administrator/converting-variable-types-in-vbscript-from-one-type-another-type/]the chart[/url] on this page for a list)