Mark Duplicate Entries in Google Spreadsheet

Question

I have a spreadsheet with entries in column F that could be duplicates later on in F. I\'m looking to make something that does something like this pseudocode:

Whi

Answer 1

You don't need JS for this. You can do it with the built-in spreadsheet formulas.

It sounds like you want a similar answer that I gave to this question, with the difference being that you are checking two columns instead of just one.

You want this:

=if(AND(COUNTIF($A$1:$A2,A2)=1, COUNTIF($B$1:$B2,B2)=1), "", "Yes")

The key thing to notice is the use of the AND forumla.

This will fill down and look like this in subsequent rows:

=if(AND(COUNTIF($A$1:$A3,A3)=1, COUNTIF($B$1:$B3,B3)=1), "", "Yes")
=if(AND(COUNTIF($A$1:$A4,A4)=1, COUNTIF($B$1:$B4,B4)=1), "", "Yes")
...

And these are the results using your spreadsheet data as an example. This is assuming the formula was inserted into the Duplicate? column (C2) and filled down:

   A                          B               C
1  Contact                    Name            Duplicate?
2  email@example.com          John  
3  repeat.email@example.com   Repeated Name 
4  repeat.email@example.com   Jane            Yes
5  email3@example.com         Repeated Name   Yes