A common use of data validation is to create a drop-down list. Use it to restrict the type of data that users enter into an Excel cell.

Follow the steps below to create a drop-down list using data validation in Excel. If you want to add a message pop up, you can click the Input Message tab and check the checkbox for “Show input ...

Data validation is one of the most effective ways to protect Web applications from attack. Ensuring only the data you expect is entered into a form or provided via some other input mechanism ...