Check if a string contains specific characters using VBS script

Question

My script is doing the following point :

1. Retrieve all my selected folder files
2. Class them by date (From the recent one to the older)
3. Show them in a window

Here is my VBS Script (I retrieve it here):

    Option Explicit

    Const PathMDB   = "C:\Users\C8461789\Desktop\test_script" 

    MsgBox TriRepertoire,,"Enumération " & PathMDB
    '---lister les fichiers du répertoire ---
    Function TriRepertoire()
    Dim fso, fichier, fileItem
    Dim i, imax, z, valeur, cible, liste
    Set fso = CreateObject("Scripting.FileSystemObject")

    imax = 0
    'début de l'énumération
    For Each fichier In fso.GetFolder(PathMDB).Files
    Set fileItem = fso.GetFile(fichier)

    imax = imax + 1
    ReDim Preserve Tableau(2, imax)
    Tableau(1, imax) = Fichier.Name
    Tableau(2, imax) = FileItem.DateLastModified

    '---trier les fichiers par ordre décroissant de création ---
    Do
    Valeur = 0
    For i = 1 To imax - 1
        If InStr(Tableau(1,i), "average", vbTextCompare) > 0 Then
            If CDate(Tableau(2, i)) < CDate(Tableau(2, i + 1)) Then
                For z = 1 To 2
                   Cible = Tableau(z, i)
                   Tableau(z, i) = Tableau(z, i + 1)
                   Tableau(z, i + 1) = Cible
                Next
                Valeur = 1
            End If
        End If
    Next 
    Loop While Valeur = 1
    Set fileItem = nothing
    Next

    'Affichage du résultat classé
    For i = 1 To imax
    'If IsNull(Tableau) Then
        liste = liste &vbTab& Tableau(1, i) &vbCr 
    'End If
    Next
    TriRepertoire = liste

    Set fso = nothing 
    End Function

In order to filter by name my retrieved files, I would like to add the following condition :

• For each file name, if it contains "average", add the file name to the table
• Else, do nothing

I tried to use

If InStr(Tableau(1,i), "average", vbTextCompare) > 0 Then

But it shows me this error :

Answer 1

You are using InStr incorrectly. Your code:

InStr(Tableau(1,i), "average", vbTextCompare)

The signature for InStr is:

InStr([start,]string1,string2[,compare])

But the gotcha here is that it has two optional parameters, one of them being in the front, with a special condition:

Optional. Specifies the starting position for each search. The search begins at the first character position (1) by default. This parameter is required if compare is specified

So because you are using the fourth parameter with the value vbTextCompare, you need to specify the starting point in the first parameter as well, which would be 1 (first character) in your case. So, the corrected code is:

InStr(1, Tableau(1,i), "average", vbTextCompare)

The error message you see basically complains that the first parameter is expected to be an integer, but you are feeding it a string.

See InStr docs.