Trim all types of whitespace, including tabs

Question

In VB6, the Trim() function trims spaces off the front and back of a string. I am wondering if there is a function that will trim not just spaces, but all whitespace (tabs in this case) off of each end of a string.

Answer 1

I use this function:

Private Function TrimAll(Text As String) As String

Const toRemove As String = " " & vbTab & vbCr & vbLf 'what to remove

Dim s As Long: s = 1
Dim e As Long: e = Len(Text)
Dim c As String

If e = 0 Then Exit Function 'zero len string

Do 'how many chars to skip on the left side
    c = Mid(Text, s, 1)
    If c = "" Or InStr(1, toRemove, c) = 0 Then Exit Do
    s = s + 1
Loop
Do 'how many chars to skip on the right side
    c = Mid(Text, e, 1)
    If e = 1 Or InStr(1, toRemove, c) = 0 Then Exit Do
    e = e - 1
Loop
TrimAll = Mid(Text, s, (e - s) + 1) 'return remaining text

End Function

Usage:

    Debug.Print "|" & TrimAll("") & "|" 'prints ||
    Debug.Print "|" & TrimAll(" ") & "|" 'prints ||
    Debug.Print "|" & TrimAll("a") & "|" 'prints |a|
    Debug.Print "|" & TrimAll("a ") & "|" 'prints |a|
    Debug.Print "|" & TrimAll(" a") & "|" 'prints |a|
    Debug.Print "|" & TrimAll(" a b ") & "|" 'prints |a b|
    Debug.Print "|" & TrimAll(vbTab & " " & "Some " & vbCrLf & " text. " & vbCrLf & " ") & "|" 'prints |Some
text.|

You can simply add the chars to be removed at the toRemove string.

It does not copy the partialy trimmed string again and again, but rather searches where the trimmed string starts and ends, and returns that portion only.

Answer 2

You'll have to combine the Trim function with the Replace function:

s = "   ABC  " & vbTab & "   "
MsgBox Len(s)

MsgBox Len(Trim$(s))

s = Replace$(Trim$(s), vbTab, "")
MsgBox Len(s)

Note: The above code will also remove embedded tabs. Probably can resolve this with regular expressions but here's a way to trim spaces/tabs only from the ends via looping:

Dim s As String, char As String, trimmedString As String
Dim x As Integer

s = "  " & vbTab & " ABC  " & vbTab & "a   " & vbTab

'// Trim all spaces/tabs from the beginning
For x = 1 To Len(s)
    char = Mid$(s, x, 1)
    If char = vbTab Or char = " " Then
    Else
        trimmedString = Mid$(s, x)
        Exit For
    End If
Next
'// Now do it from the end
For x = Len(trimmedString) To 1 Step -1
    char = Mid$(trimmedString, x, 1)
    If char = vbTab Or char = " " Then
    Else
        trimmedString = Left$(trimmedString, x)
        Exit For
    End If
Next

You should end up with ABC{space}{space}{tab}a