Loop through files using instead of Dir

Question

Upon understanding of Dir function: Dir [( path [, attributes ] ) ]
[Path] is optional and if it is not found, the DIR function will return a zero-length string.
I replaced StrFile = Dir with StrFile = "" on the below code, and it just debug.printed only one file on my directory.

So, What is the meaning of StrFile = Dir?

Sub LoopThroughFiles()
    Dim StrFile As String
    StrFile = Dir("c:\testfolder\*")
    Do While Len(StrFile) > 0
        Debug.Print StrFile
        StrFile = ""
    Loop

End Sub

Answer 1

Upon reading the documentation @Dir function (Visual Basic for Applications) it seems initial call to Dir

StrFile = Dir("c:\testfolder\*")

the first file that matches the pathname will be returned. A while loop is started because at least one file exists, and successive calls to Dir without an argument return other filenames that match the filepath. Up to that point, Dir returns "" to the StrFile and the while loop is broken.

I think that when you set

StrFile = ""

It skips the fetching of additional filenames that match filepath and only the first file that matches is printed.