Visual Basic scripting dynamic array

scripting, vbscript

Solution

You can't re-dimension a fixed-size array (`Dim vprglist(10)`). If you want a dynamic array, define a "normal" variable and assign an empty array to it:

Dim vprglist : vprglist = Array()

or define it directly with `ReDim`:

ReDim vprglist(-1)

Then you can re-dimension the array like this:

If vprogram.LastRunTime = "" Then
  ReDim Preserve vprglist(UBound(vprglist)+1)
  vprglist(UBound(vprglist)) = vprogram.FullName
  i = i + 1
End If

`ReDim Preserve` will copy all elements of the array into a new array, though, so it won't perform too well in the large scale. If performance is an issue, you'd better use the `System.Collections.ArrayList` class instead:

Dim vprglist : Set vprglist = CreateObject("System.Collections.ArrayList")
...
If vprogram.LastRunTime = "" Then
  vprglist.Add vprogram.FullName
  i = i + 1
End If

Problem

So i have a vb script that sweeps through RAP (Run advertised programs) and if the program has no last run time, but that program's full name into an array, then i have this array echo to a message box. I intialize the array to store 10 values, however to keep the message box clean i wanted to ReDim the array size once it had found all the programs (shoudn't ever be more than 3 but who knows with clients). However i can't seem to get the array to resize and it prints a message box with 10 array slots + the program it found. ``` Dim vprglist(10) Dim i Dim strBuf Dim intIndex Set vprograms = oUIResource.GetAvailableApplications i = 0 For Each vprogram In vprograms If vprogram.LastRunTime = "" Then vprglist(i) = vprogram.FullName i = i + 1 End If Next ReDim Preserve vprglist(i) If vprglist <> Null Then For intIndex = LBound(vprglist) To UBound(vprglist) strBuf = strBuf & " - " & vprglist(intIndex) & vbLf Next vmsgbox = MsgBox("Do you want to Install(Yes) or Defer(No) the follow software: " & vbLf & strBuf,64+4) Select Case vmsgbox ```

Original source