WD: Creating Recursive Functions Using WordBasic

ID: Q72280

The information in this article applies to:

Microsoft Word for Windows versions 1.0, 1.1, 1.1a, 2.0, 2.0a, 2.0a-CD, 2.0b, 2.0c, 6.0, 6.0a, 6.0c
Microsoft Word for Windows NT, version 6.0
Microsoft Word for Windows 95, versions 7.0, 7.0a
Word for the Macintosh, versions 6.0, 6.0.1, 6.0.1a

SUMMARY

In Microsoft Word, you can write macros that use recursive functions.

MORE INFORMATION

In WordBasic, functions can call other functions; additionally, as in many other languages, these functions can call themselves. Any function that makes a call to itself is considered recursive. For more information on recursive functions, refer to the book, "Microsoft Quick C Programming" (published by the Waite Group), pages 164-167.

The following two examples figure the factorial of a number. The first example does not use recursion; the second example uses recursion.

Sample Macros to Figure the Factorial of a Number (n!)

Method 1: Finding (n!) Without Recursion

   Sub MAIN()
      Input "Find Factorial Of: ", a     'Allows user input
      result = Factorial(a)              'Only function call
      Print result                       'Prints the final result
   End Sub

   Function Factorial(a)
      If a = 0 Then                      'If a = 0 return 1 (0!=1)
         sum = 1
      Else                               'calculate with loop
         sum = a
         For x = a - 1 To 1 Step - 1
            sum = sum * x
         Next x
      End If
      Factorial = sum
   End Function

Method 2: Finding (n!) with Recursion

   Sub MAIN()
      Input "Find Factorial Of: ", a     'Allows user input
      result = Factorial(a)
      Print result
   End Sub

   Function Factorial(a)
      If a = 0 Then                      '(0!=1 so return 1)
         result = 1
      Else
         result = a * Factorial(a - 1)   'if not 0 then
      End If                             'multiply "a" by
      Factorial = result                 'factorial of a-1
   End Function

Both methods return the same result; however, the recursive method is slightly more efficient.

REFERENCES

The Waite Group's book "Microsoft Quick C Programming," pages 164-167

Additional query words:

Keywords          : kbmacro wordnt kbmacroexample winword ntword macword word6 winword2 word7 word95 
Version           : WINDOWS:1.0,1.1,1.1a,2.0,2.0a,2.0a- CD,2.0b,2.0c,6.0,6.0a,6.0c,7.0,7.0a; MACINTOSH:6.0,6.0.1,6.0.1a
Platform          : MACINTOSH Win95 WINDOWS winnt
Issue type        : kbhowto

Last Reviewed: February 4, 1998