Microsoft KB Archive/47949

= Microsoft Knowledge Base =

Recursive Routines Possible in Excel Function Macros
Last reviewed: July 7, 1997

Article ID: Q47949

The information in this article applies to:


 * Microsoft Excel for Windows, versions 2.x, 3.0, 4.0, 5.0
 * Microsoft Excel for Windows 95, version 7.0
 * Microsoft Excel for the Macintosh, versions 2.x, 3.0, 4.0, 5.0

SUMMARY
A Microsoft Excel function macro can call itself in a recursive fashion to compute an answer. For example, the following macro computes the factorial of a number:

A1: factorial A2: =ARGUMENT(&quot;parameter&quot;) A3: =IF(parameter=1,RETURN(1)) A4: =RETURN(parameter*factorial(parameter-1)) Note: This function macro is provided only as an example. Microsoft Excel has a built-in FACT function that computes the factorial of a number more efficiently.

The macro must be defined as a function macro.

If you are using Microsoft Excel versions 5.0 or 7.0, you can use the equivalent macro in Visual Basic for Applications:

Function factorial(parameter As Integer) As Integer If parameter = 1 Then factorial = 1 Else factorial = parameter * factorial(parameter - 1) End If  End Function Microsoft provides examples of Visual Basic for Applications procedures for illustration only, without warranty either expressed or implied, including, but not limited to the implied warranties of merchantability and/or fitness for a particular purpose. The Visual Basic procedures in this article are provided 'as is' and Microsoft does not guarantee that they can be used in all situations. While Microsoft support engineers can help explain the functionality of a particular macro, they will not modify these examples to provide added functionality, nor will they help you construct macros to meet your specific needs. If you have limited programming experience, you may want to consult one of the Microsoft Solution Providers. Solution Providers offer a wide range of fee-based services, including creating custom macros. For more information about Microsoft Solution Providers, call Microsoft Customer Information Service at (800) 426-9400.