In This Chapter
Errors happen. And when you create Excel formulas, errors happen frequently. This chapter describes common formula errors and discusses tools and methods that you can use to help create formulas that work as they are intended to.
Debugging refers to identifying and correcting errors in a computer program. Strictly speaking, an Excel formula is not a computer program. Formulas, however, are subject to the same types of problems that occur in a computer program. If you create a formula that does not work as it should, you need to identify and correct the problem.
The ultimate goal in developing a spreadsheet solution is to generate accurate results. For simple worksheets, this is not difficult, and you can usually tell whether the formulas are producing correct results. But as your worksheets grow in size or complexity, ensuring accuracy becomes more difficult.
Making a change in a worksheet—even a relatively minor one—may produce a ripple effect that introduces errors in other cells. For example, accidentally entering a value into a cell that previously held a formula is all too easy to do. This simple error can have a major impact on other formulas, and you may not discover the problem until long after you made the change—or you may never discover the problem.