ACC: Sample Function to Reverse the Characters in a String

ID: Q109729

The information in this article applies to:

SUMMARY

Moderate: Requires basic macro, coding, and interoperability skills.

This article shows you how to create a function called ReverseString() that 

 reverses the characters in a string, and describes how to use the ReverseString() function to sort records in a query with the results of the function.
This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to your version of the "Building Applications with Microsoft Access" manual.

NOTE: Visual Basic for Applications is called Access Basic in Microsoft Access versions 1.x and 2.0. For more information about Access Basic, please refer to the "Introduction to Programming" manual in Microsoft Access version 1.x or the "Building Applications" manual in Microsoft Access version 2.0

MORE INFORMATION

The ReverseString() function returns a string with the characters reversed from the original argument string. For example, if the string "ABCD" were passed to the function, the string "DCBA" would be returned.

The following example demonstrates how to create and use the ReverseString() function:

1. Open the sample Northwind.mdb database (or NWIND.MDB in versions 1.x 

   and 2.0).
2. Create a module and type the following line in the Declarations section, 
   if it isn't already there:

      Option Explicit
3. Type the following procedure: 

      Function ReverseString (MyString As String)
          Dim StringReversed As String
          Dim MyStringLength As Integer, X
          MyStringLength = Len(MyString)
          For x = 1 To MyStringLength
            StringReversed = Mid(MyString, x, 1) & StringReversed
          Next x
          ReverseString = StringReversed
      End Function
4. Create the following new query based on the Categories table: 

      Query: Query1
      -------------------------------------------
      Field: CategoryName
         Show: (selected)
      Field: Expr1: ReverseString([CategoryName])
         Sort: Ascending
         Show: (not selected)

      NOTE: In version 1.x and 2.0, type a space in the Category Name
      field name.
5. On the Query menu, click Run. Note that the following items are 
   returned:

      CategoryName
      ------------
      Seafood
      Produce
      Beverages
      Grains/Cereals
      Confections
      Dairy Products
      Condiments
      Meat/Poultry
The returned records are sorted in ascending order on the CategoryName field, but the field is sorted from right to left, rather than from left to right. For example, Seafood is sorted on "d," Produce on "e," Beverages on "s," and so on.

REFERENCES

For more information about the Mid() function, search the Help Index for "Mid Function," or ask the Microsoft Access 97 Office Assistant.

Additional query words: sorting backwards 

Keywords          : kbprg ExrStrg 
Version           : 1.0 1.1 2.0 7.0 97
Platform          : WINDOWS
Hardware          : x86
Issue type        : kbinfo

Last Reviewed: November 21, 1998