Use Excel data validation to prevent duplicate values in ... The COUNTIF() function counts the number of cells in a range that meet a specific condition. You supply the range and a condition ...

Use data validation to limit choices during data entry. To create a data validation drop-down list in Excel, you need two things: A list of values and a blank cell to use as the data entry 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 ...