Here is a very extensive explanation of the function:

http://www.xldynamic.com/source/xld.SUMPRODUCT.html

--
HTH,

RD

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"Tan" wrote in message
...
Hi All,

I have did some read up about having '--' in writing up the SUM PRODUCT
function on some websites. But still trying to figure out the reason
behind
having '--' in our SUMPRODUCT function. For example,

=SUMPRODUCT(--(PLList=B15),(ShipmKList),--(CountryList=$C$2))

PLList a named range in my database for my product code field. ShipmKList
is
named range in my database for my Shipped Amt field. CountryList is named
range for my country field.

I got this function recommended by someone to extract out the total
shipped
amt for a particular country and for the product codes i wish to sum. I
input
my Product Code in cell B15 and input my country in cell C2 on another
sheet.

Second question is how many more criteria can i set based on the SUM
PRODUCT
function above and how do i go about adding more criteria.

Thanks in advance!