How can I find if an entry in column A exists in column B?

Hi - I would like to find duplicates of names that sit within two columns, that I have in Libre Office Math (v3.5 I believe). I have a list of names that sit in column a, and a list that sits in column b, but do not necessarily sit across from one another in a row. I need to identify where there are duplicates (and highlight them some how) so I can see which names appear in both columns.

Many thanks for your help!

Thanks Mahfiaz. Unfortunately I’m getting #NAME? and #N/A within the column 3 cells. The only thing that I can see is that the programme is automatically changing the ; to a , in the formula (not sure if this is normal or not, I’m a complete novice) - any advice? Thanks again for your help.

Same question asked here.

Let’s say A1:A100 is the first row, B1:B100 the second one and from C1 down to C100 you will drag the following formula: =IFERROR(MATCH(B1;$A$1:$A$100;0);"")

If there is no duplicate, the cell will remain empty, otherwise it will show the number of row where the first duplicate is in first column.

And if you need some visual indicator such as red background, use conditional formatting.