Excel® 2010 Bible

Chapter 40. Creating Custom Worksheet Functions

IN THIS CHAPTER

Overview of VBA functions

About function procedures

Function procedure arguments

Debugging custom functions

Pasting custom functions

As mentioned in the preceding chapter, you can create two types of VBA procedures: Sub procedures and Function procedures. This chapter focuses on Function procedures.

40.1. Overview of VBA Functions

Function procedures that you write in VBA are quite versatile. You can use these functions in two situations:

• You can call the function from a different VBA procedure.

• You can use the function in formulas that you create in a worksheet.

This chapter focuses on creating functions for use in your formulas.

Excel includes hundreds of predefined worksheet functions. With so many from which to choose, you may be curious as to why anyone would need to develop additional functions. The main reason is that creating a custom function can greatly simplify your formulas by making them shorter, and shorter formulas are more readable and easier to work with. For example, you can often replace a complex formula with a single function. Another reason is that you can write functions to perform operations that would otherwise be impossible.

NOTE

This chapter assumes that you're familiar with entering and editing VBA code in the Visual Basic Editor (VB Editor). See Chapter 39 for an overview of the VB Editor.

40.2. An Introductory Example

Creating custom functions is relatively easy after you understand VBA. ...