Microsoft Office Tutorials and References
In Depth Information
Chapter 23: Function Procedure Basics
In This Chapter
Why you may want to create custom functions
An introductory VBA function example
About VBA Function procedures
Using the Insert Function dialog box to add a function description and assign a function
Tips for testing and debugging functions
Creating an add-in to hold your custom functions
Previous chapters in this topic examine Excel’s worksheet functions and how you can use them
to build more complex formulas. These functions provide a great deal of flexibility when creating
formulas. However, you may encounter situations that call for custom functions. This chapter
discusses why you may want to use custom functions, how you can create a VBA Function
procedure, and methods for testing and debugging them.
Why Create Custom Functions?
You are, of course, familiar with Excel’s worksheet functions — even novices know how to use the
most common worksheet functions, such as SUM, AVERAGE, and IF. Excel 2010 includes more
than 400 predefined worksheet functions — everything from ABS to ZTEST.
You can use VBA to create additional worksheet functions, which are known as custom functions
or user-defined functions (UDFs). With all the functions that are available in Excel and VBA, you
may wonder why you would ever need to create new functions. The answer: to simplify your
work and give your formulas more power.