Excel® 2010 Bible

Chapter 25. Using Data Validation

IN THIS CHAPTER

An overview of Excel's data validation feature

Practical examples of using data validation formulas

This chapter explores a very useful Excel feature: data validation. Data validation enables you to add dynamic elements to your worksheet without using any macro programming.

25.1. About Data Validation

The Excel data validation feature allows you to set up certain rules that dictate what can be entered into a cell. For example, you may want to limit data entry in a particular cell to whole numbers between 1 and 12. If the user makes an invalid entry, you can display a custom message, such as the one shown in Figure 25.1.

Figure 25.1. Displaying a message when the user makes an invalid entry.

Excel makes it easy to specify the validation criteria, and you can also use a formula for more complex criteria.

The Excel data validation feature suffers from a potentially serious problem: If the user copies a cell that does not use data validation and pastes it to a cell that does use data validation, the data validation rules are deleted. In other words, the cell then accepts any type of data.

25.2. Specifying Validation Criteria

To specify the type of data allowable in a cell or range, follow the steps below while you refer to Figure ...