Q188007: HOWTO: Simulate Visual Basic 6.0 String Functions in VB5
Article: Q188007
Product(s): Microsoft Visual Basic for Windows
Version(s):
Operating System(s):
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001
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The information in this article applies to:
- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0
- Microsoft Visual Basic Standard Edition for Windows, version 4.0
- Microsoft Visual Basic Professional Edition for Windows, version 4.0
- Microsoft Visual Basic Enterprise Edition for Windows, version 4.0
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SUMMARY
=======
Visual Basic version 6.0 introduces a number of new string functions to simplify
string manipulation in your code. This article describes how the same
functionality can be used with earlier versions of Visual Basic.
MORE INFORMATION
================
The following additional string functions are present in Visual Basic 6.0:
Function Description
-------- -----------
Join Used to join arrays elements.
Split Split a string into a variant array.
InStrRev Similar to InStr but searches from end of string.
Replace To find a particular string and replace it.
Reverse To reverse a string.
If these functions are coded and added in a module, all the above functions can
be used in the project as if they are intrinsic functions.
1. Start a new project. Form1 is created by default.
2. Add a new module to the project and add the following code to the module:
Option Explicit
Public Function Join(source() As String, Optional _
sDelim As String = " ") As String
Dim sOut As String, iC As Integer
On Error GoTo errh:
For iC = LBound(source) To UBound(source) - 1
sOut = sOut & source(iC) & sDelim
Next
sOut = sOut & source(iC)
Join = sOut
Exit Function
errh:
Err.Raise Err.Number
End Function
Public Function Split(ByVal sIn As String, Optional sDelim As _
String, Optional nLimit As Long = -1, Optional bCompare As _
VbCompareMethod = vbBinaryCompare) As Variant
Dim sRead As String, sOut() As String, nC As Integer
If sDelim = "" Then
Split = sIn
End If
sRead = ReadUntil(sIn, sDelim, bCompare)
Do
ReDim Preserve sOut(nC)
sOut(nC) = sRead
nC = nC + 1
If nLimit <> -1 And nC >= nLimit Then Exit Do
sRead = ReadUntil(sIn, sDelim)
Loop While sRead <> ""
ReDim Preserve sOut(nC)
sOut(nC) = sIn
Split = sOut
End Function
Public Function ReadUntil(ByRef sIn As String, _
sDelim As String, Optional bCompare As VbCompareMethod _
= vbBinaryCompare) As String
Dim nPos As String
nPos = InStr(1, sIn, sDelim, bCompare)
If nPos > 0 Then
ReadUntil = Left(sIn, nPos - 1)
sIn = Mid(sIn, nPos + Len(sDelim))
End If
End Function
Public Function StrReverse(ByVal sIn As String) As String
Dim nC As Integer, sOut As String
For nC = Len(sIn) To 1 Step -1
sOut = sOut & Mid(sIn, nC, 1)
Next
StrReverse = sOut
End Function
Public Function InStrRev(ByVal sIn As String, sFind As String, _
Optional nStart As Long = 1, Optional bCompare As _
VbCompareMethod = vbBinaryCompare) As Long
Dim nPos As Long
sIn = StrReverse(sIn)
sFind = StrReverse(sFind)
nPos = InStr(nStart, sIn, sFind, bCompare)
If nPos = 0 Then
InStrRev = 0
Else
InStrRev = Len(sIn) - nPos - Len(sFind) + 2
End If
End Function
Public Function Replace(sIn As String, sFind As String, _
sReplace As String, Optional nStart As Long = 1, _
Optional nCount As Long = -1, Optional bCompare As _
VbCompareMethod = vbBinaryCompare) As String
Dim nC As Long, nPos As Integer, sOut As String
sOut = sIn
nPos = InStr(nStart, sOut, sFind, bCompare)
If nPos = 0 Then GoTo EndFn:
Do
nC = nC + 1
sOut = Left(sOut, nPos - 1) & sReplace & _
Mid(sOut, nPos + Len(sFind))
If nCount <> -1 And nC >= nCount Then Exit Do
nPos = InStr(nStart, sOut, sFind, bCompare)
Loop While nPos > 0
EndFn:
Replace = sOut
End Function
3. Add two CommandButtons to Form1. Add the following code to the General
Declaration section of Form1:
Option Explicit
Dim MyArray(2) As String, MyStr As String, MyVar As Variant
Private Sub Command1_Click()
MyArray(0) = "item1"
MyArray(1) = "item2"
MyArray(2) = "item3"
MyStr = Join(MyArray, ";")
Debug.Print MyStr
End Sub
Private Sub Command2_Click()
Dim i As Integer
MyVar = Split(MyStr, ";")
For i = LBound(MyVar) To UBound(MyVar)
Debug.Print MyVar(i)
Next
End Sub
Private Sub Form_Load()
Command1.Caption = "Join"
Command2.Caption = "Split"
End Sub
4. Press the F5 key to run the project. Click on Join, and note in the debug
window that the array elements are joined. Click on Split to split a string
into a variant array.
5. Pause the project by pressing the CTRL+BREAK key combination or clicking the
Pause button on the toolbar. Test the remaining functions by typing the
following lines in the immediate window and verifying the results:
?instrrev("//drive/dir","/")
8
?strreverse("input string")
gnirts tupni
?replace("input string"," ", "-",4,1)
input-string
NOTE: The errors generated may not exactly coincide with those generated by
the Visual Basic 6.0 intrinsic string functions.
Additional query words: kbDSupport kbDSD beta99 kbVBp kbVBp400 kbVBp500 kbVBp600 kbVBA
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Keywords : kbGrpDSVB
Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Issue type : kbhowto
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