=sumproduct in Excel 2000

[LPS]

In the following "sumproduct" function, what do the "--" mean?

=SUMPRODUCT(--('Evaluation Detail'!$B$7:$B$499<>0),--('Evaluation
Detail'!$F$7:$F$499="Jane Doe"))

Thank you,

 

[Dave Peterson]

--('Evaluation Detail'!$B$7:$B$499<>0)
returns 493 true/falses.

The -- stuff changes the booleans to 1's and 0's.

'cause =sumproduct() likes to work with numbers.

Bob Phillips explains =sumproduct() in much more detail here:
http://www.xldynamic.com/source/xld.SUMPRODUCT.html

And J.E. McGimpsey has some notes at:
http://mcgimpsey.com/excel/formulae/doubleneg.html

 

[LPS]

Thank you, Dave. I think I have it now!

Cheers,