ACC: How to Convert Letters to Numbers in Phone Numbers (132055)

SUMMARY

This article shows you how to create two user-defined functions that you can use to convert any letter in a phone number to its corresponding digit on a telephone keypad or rotary dial. For example, you can convert the number "206-ACC-ESS2" to its equivalent 206-222-3772 so that dialing is easier.

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 version 2.0. For more information about Access Basic, please refer to the "Building Applications" manual.

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The method in this article uses two user-defined functions. The first function translates letters into numbers; the second function applies the translation to an entire phone number. The method works with phone numbers that have different formats (for example, "800-555-GIGO" or "800555GIGO") as well as with phone numbers that have different lengths (for example, "555-GIGO" or "011-01-704-555-GIGO").

To convert letters in a phone number to numbers, follow these steps:

Create a module and type the following line in the Declarations section if it is not already there:
Option Explicit

Type the following procedure:

       ' Translates a letter to a digit.
      Function XlateDigit(ByVal C As String) As String
        C = UCase(C)
        Select Case C
          Case "A" To "P"
            XlateDigit = Chr$((Asc(C) + 1) \ 3 + 28)
          Case "R" To "Y"
            XlateDigit = Chr$(Asc(C) \ 3 + 28)
          Case "Q", "Z"
            XlateDigit = "0"
          Case Else
            XlateDigit = C
        End Select
      End Function

Type the following procedure:


      ' Applies the translated digit to a phone number.
      Function PhoneLettersToDigits(ByVal PhoneNo As Variant) As Variant
        Dim I as Integer
          If VarType(PhoneNo) = 8 Then  ' A string.
             For I = 1 To Len(PhoneNo)
               Mid(PhoneNo, I, 1) = XlateDigit(Mid(PhoneNo, I, 1))
             Next I
          End If
        PhoneLettersToDigits = PhoneNo
      End Function

To test these functions, type the following line in the Debug window (or Immediate window in Microsoft Access 2.0), and then press ENTER:
? PhoneLettersToDigits("PRO-GRA-MMER")

Note that the following number is displayed:
776-472-6637

ACC: How to Convert Letters to Numbers in Phone Numbers (132055)

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