Strip Non AlphaNumeric Characters from a String

Category:

String Manipulation

Type:

Snippets

Difficulty:

Beginning

Author:

Intelligent Solutions Inc.

Version Compatibility:

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

Public Function OnlyAlphaNumericChars(ByVal OrigString As _
  String) As String
'***********************************************************
'INPUT:  Any String
'OUTPUT: The Input String with all non-alphanumeric characters 
'        removed
'EXAMPLE Debug.Print OnlyAlphaNumericChars("Hello World!")
         'output = "HelloWorld")
'NOTES:  Not optimized for speed and will run slow on long
'        strings.  If you plan on using long strings, consider 
'        using alternative method of appending to output string,
'        such as the method at
'        http://www.freevbcode.com/ShowCode.Asp?ID=154
'***********************************************************
    Dim lLen As Long
    Dim sAns As String
    Dim lCtr As Long
    Dim sChar As String
    
    OrigString = Trim(OrigString)
    lLen = Len(OrigString)
    For lCtr = 1 To lLen
        sChar = Mid(OrigString, lCtr, 1)
        If IsAlphaNumeric(Mid(OrigString, lCtr, 1)) Then
            sAns = sAns & sChar
        End If
    DoEvents '(optional, but if processing long string,
    'necessary to prevent program from appearing to hang)
    'if used, write your app so no re-entrancy into this function
    'can occur)
    Next
        
    OnlyAlphaNumericChars = sAns

End Function

Private Function IsAlphaNumeric(sChr As String) As Boolean
    IsAlphaNumeric = sChr Like "[0-9A-Za-z]"
End Function