Page 74 - Excel for Scientists and Engineers: Numerical Methods

CHAPTER 2 FUNDAMENTALS .OLPROGRAMMING WITH VBA 51

How to Create an Add-In Macro
To save a workbook as an Add-In, choose Save As.. . from the File menu.
Choose Microsoft Excel Add-In from the Save File As Type drop-down list box,
then press OK. In Excel for Windows, Add-In workbooks are automatically
given the filename extension .xla.
When you save a workbook as an Add-In, the default location is the AddIns
folder.
Command macros can also be saved as Add-Ins.

Testing and Debugging

When an error occurs during execution of a procedure, VBA will stop
execution and display a run-time error message. There are a large number (over
50) of these run-time error messages. Some (but not all) of these error messages
are self-explanatory. Here are some examples:
Subscript out of range Attempted to access an element of an
array outside its specified dimensions.
Property or method not found Object does not have the specified
property or method.
Argument not optional A required argument was not provided.
The line of code in which the error occurred, or the first line of the
procedure (containing the Sub or Function keyword) will be highlighted,
usually in yellow (see Figure 2-22). After you have corrected the error in your
VBA code, the line will still be highlighted. Press F5 to continue execution.

Figure 2-22. VBA code with a highlighted line.