Mark certain cells

[frederico roldao]

I have a sheet with 3 columns.

On column "A" I have 1000 email addresses, on column "B" I have 200 email
addresses.

On column "C" I want to have a formula that will mark the cell if the
address on the adjacent cell (in column B) also exists somewhere in column A.

How do I go about this?

 

[Gary''s Student]

In C1 enter:
=IF(COUNTIF(A:A,B1)>0,"a","") and set the font to Marlett

Then copy down

 

[Mike H]

Hi,

=IF(COUNTIF($A$1:$A$1000,B1)>0,"Duplicate","")

Drag down to the length of column B

Mike

 

[Jarek Kujawa]

one way - in C1:

=IF(COUNTIF($A$1:$A$1000,B1)>0,"yes","")

then drag/copy down

 

[frederico roldao]

I'm sorry, I didn't explain myself properly!

I mean to have a mark on column C on the rows where in column A there is a
value that is also in column B (anywhere on column B, not necessarily side by
side)

 

[Mike H]

And if you try any of the suggestions provided you'll find that's exactl what
they do!!

 

[frederico roldao]

actually the formula that worked was =IF(COUNTIF(B:B;A1)>0;"y";""), which is
a bit different from what was advised, but the advice served as a starting
point, so, thanks!