* works where comma doesn't when there are conditions. So

=SUMPRODUCT(A1:A10,B1:B10)

works fine when they are all numbers. But if you want to test for A1:A10
10 say the test

A1:A1010 returns TRUE FALSE which have to be transformed into numbers for
SUMPRODUCT to work. One way is to multiply the arrays (TRUE*1=1, FALSE*1=0),
another is to double negate it (--TRUE), another is to add 0 (TRUE+0),
another is to raise to the 0th power (TRUE^2). All of these have the effect
of transforming to a number which SUMPRODUCT is happier to work with.


--
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HTH

Bob


(there's no email, no snail mail, but somewhere should be gmail in my addy)



wrote in message
...
On Feb 5, 1:12 pm, Ollie4 wrote:
so what does
sumproduct(--(A1:A1000="West"),--(B1:B1000="Blue"),C1:C1000)
deferrer from
sumproduct((A1:A1000="West")*(B1:B1000="Blue")*(C1 :C1000))?

Related question:

Why does the "*" work, but if you use "," instead you don't get the
right answer. I thought sumproduct multiplied the entries so in a
way, I thought they'd still get multiplied "the right way".

PS, thanks for the link Bob Phillips.