Use Excel data validation to prevent duplicate values in a column Your email has been sent Prevent duplicates before they happen by combining a simple function with data validation. Excel has built-in ...

This calculation can be useful, for example, if you are deciding on the number of sportspersons selected (or rejected) for an event or the number of products approved selected or rejected for export.

The syntax for counting the number of unique values from a list of a column using the array formula is as follows: =SUM(IF(COUNTIF(<first cell from which you count the number of unique values>:<last ...