Effective method to compare worksheets?

[hideki]

Hi,

I've two worksheets for current month and previous month. I'd like to compare this two sheets and highlight the different. The key to compare is Product No in column A.

I could do this using loop to check row by row in the previous month sheet. And using vlookup to check if the Product No exist in current month sheet. I wonder if there is more effective method to accomplished this task. I think the looping row by row is quite slow. And in some occasion, the Product No was blank that make my vlookup not working properly (I think).

Your help are appreciated.

[Nick Hebb]

Have you tried the loop yet? Often things that I think will execute
slowly actually end up being quite fast.

----

Nick hebb
BreezeTree Software
http://www.breezetree.com

[hideki]

Thank you Nick for your respond. Yes I'd tried the loops thing, and just like what you said, it ran quite fast. At least, not annoying me at all. But I just wonder if my rows become bigger in number, can it still give the same result?

I'm a beginner in Excel programming and still learning what is the right and good programming style. If there is no other effective method, I'll stick to the row by row looping in my VBA programming.