Comparing and aligning data in EXCEL?

Question

I hope someone can help me with this.
Suppose I have two columns in excel, A and B. Column has numbers 1, 9, 7, and 5. Column B has 7, blank, blank, and 1. I want to sort them so the numbers in both columns align with each other and leave the blanks if there is no matching number.

Does anyone know how to do this because I've been fiddling with this thing for over an hour with no success. Either I get a true, false, or it shows me the numbers that have duplicates, or it sorts it but doesn't match the numbers with each other.

Tried
=IF(COUNTIF(b:b,A1),A1,"")
That shows me the results in column C, which was cool :P
But how can I get it to actually sort those two column (without creating another one) and match the numbers up side by side if they match, and if they don't match, leave a blank?

Answer 1

try this formula in C1:

=IF(COUNTIF(b:b,A1),A1,"")

copy it down

edit:
can you just hide column b?
or you can copy column c and right click/paste special.../values over column b.

or is there more complicated to your data like a table or something?