[AccessD] Count the occurrences of each character in a string

[Stuart McLachlan]

Sorry. PB = PowerBASIC. I re-wrote the VBA to use with my PowerBASIC compiler.

It's just a minor modification  which  replaces the  very similar block in the original post.
ie. the function will be as follows.  (It's just the insertion of an IF...Then construct around the 
"y" loop.)

Function Lettercount(sInputString As String, CaseSensitive As Boolean) As Long
    Dim lStr As Long, x As Long, y As Long, compare As Long
    Dim sTxt As String
    Dim freq() As Long

    'Initialise
    sTxt = sInputString 'we are going to modify the string!
    If CaseSensitive = True Then
        compare = vbBinaryCompare
    Else
        compare = vbTextCompare
    End If
    lStr = Len(sTxt)
    ReDim freq(1 To lStr)

    'Get the letter counts
    For x = 1 To lStr
       If Asc(Mid$(sTxt, x, 1)) <> 0 Then ' skip over the "y" loop if character is already zeroed
           freq(x) = 1
           For y = x + 1 To lStr
               If StrComp(Mid$(sTxt, x, 1), Mid$(sTxt, y, 1), compare) = 0 Then
                   freq(x) = freq(x) + 1
                   Mid$(sTxt, y, 1) = Chr$(0)
              End If
           Next
      End If        ' End of skipping over the "y" loop
   Next

  'Display the results
   For x = 1 To lStr
      If Mid$(sTxt, x, 1) <> Chr$(0) Then
        Debug.Print Mid$(sTxt, x, 1) & "  -  " & str$(freq(x))
      End If
   Next
End Function


On 7 Sep 2022 at 5:56, Arthur Fuller wrote:

> Hi Stuart,
> 
> I don't know what a PB function is. Also, I'm not sure where to place
> this new code.
> 
> On Wed, Sep 7, 2022 at 3:13 AM Stuart McLachlan
> <stuart at lexacorp.com.pg> wrote:
> 
> > Just converted this to a PB function and in doing so, I realised
> > that it was slower than necessary. With a large string you will save
> > a LOT of iterations with
> >
> > For x = 1 To lStr
> >        If Asc(Mid$(sTxt, x, 1)) <> 0 Then
> >             freq(x) = 1
> >             For y = x + 1 To lStr
> >                 If StrComp(Mid$(sTxt, x, 1), Mid$(sTxt, y, 1),
> >                 compare) =
> > 0 Then
> >                     freq(x) = freq(x) + 1
> >                     Mid$(sTxt, y, 1) = Chr$(0)
> >                End If
> >             Next
> >        End If
> > Next
> >