Created by David Hager
This array formula returns the number of unique items in a worksheet range.
However, if Rng contains blank cells, this formula returns an error. In this case, use this modified version of the formula.
This array formula returns the Nth largest unique value in a column range.
To apply data validation to a column which allows only unique items to be entered, highlight that column and select Data, Validation from the menu. Choose the custom option and enter the following formula (for column A):
Created by Laurent Longre
This formula counts the number of unique items a column range, only if the cells in the lookup range contain the specified string.
rng = A1:A7
colRange = A1:A7
lookupRange = B1:B7
Don’t forget to enter those array formula with Control+Shift+Enter, not just Enter.