Excel VLOOKUP: Value Existence Check

How To Use A Vlookup Formula To Check If A Value Exists

This can be useful if the list is very long.

You should have data in the column, and have a duplicate in another.

Note: You can choose to have another kind of data in the columns.

Click on an empty column (1), and type in

=IF(ISERROR(VLOOKUP(B2,$D$2:$D$16,1,False)),False,True) (2), and then click Enter on the keyboard.

Note: This is to know if the value in B2 exist in another column.

Template

Further reading: 
How to create many to many lookup?
How to Exchange Formula to Value?
Basic concepts 
Getting started with Excel
Cell References