Garry,
More FWIW...
I ran Ron's code on my XP, i3 machine (xl2007) against 600,000 6 digit random numbers.
360,000 in col A and 240,000 in col B. It took about 7 1/2 seconds.
It returned ~87000 numbers not in col B.
'---
Jim Cone





"GS" wrote in message ...
Ron Rosenfeld wrote :
On Sun, 15 Jan 2012 19:58:40 -0500, GS wrote:

I modified my sub to use your idea to use Dictionary, but NOT put colA in a dictionary and it
shaved 11 secs off the ET...

That should preserve the duplicates in col A also, to answer your previous question.

Hhm.., that's quite true where non-matches occur. I suppose that might be a better way to go when
comparing 2 or more items. Won't help my data logger file parser, though. It just loops 1 array,
but it does parse each element into a temp array for the test. It runs blazingly fast on my
machine (1.6Ghz Intel dual-core on a Dell Precision series laptop w/2GB RAM).

--
Garry

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