Formulas with SUMPRODUCT do almost never require control+shift+enter for
it is built to operate on computed arrays. It shares this capability
with functions like LOOKUP and FREQUENCY.

If you compose formulas with SUM, COUNT, MAX, IF, etc. that must operate
on computed arrays, you'll need to signal Excel that intention with
control+shift+enter.

And yes, these are built-in features.

MDW wrote:
I'm using Excel 2000 Professional, and I'm experimenting with using the
SUMPRODUCT() function to test for multiple-criterion conditions. In the
documentation I found, it says that SUMPRODUCT is "an array function, and is
so committed by pressing Cntl-Shift-Enter".

When I do that, it adds the curly braces to either side of the function like
the documentation said it would.

However, the function seems to work OK even BEFORE I do that. So I guess my
first question is, what is thise whole "Cntl-Shift-Enter" thing all about?
Why is it needed?

My second question - is support for array functions bult into Excel? I'm
going to be giving this sheet to a bunch of people who have Excel 2000
STANDARD (I have assurances that there's no one on a version earlier than
2000). Would SUMPRODUCT still work the same way on their PCs? I intend to
test this myself, but I want to know if there are any special situations or
circumstances I should check for.

Thx.