Sumproduct formula help

[ssj011]

Good Day,

Need some clarification about the below formula,

why "–" is used in the below formula.

=SUMPRODUCT(–(A2:A5=”John”),–(B2:B5=”Johnson”),C2:C5)

Regards
Sachin

 

[Asheesh]

Hi Sachin,

This should help

http://www.k2e.com/tech-update/tips/143-using-two-minus-signs-in-excel

 

[jeffreyweir]

Here's a great link on Sumproduct that covers that behavior and a heck of a lot more:
http://blog.excelhero.com/2010/01/21/the_venerable_sumproduct/

 

[Hui]

Staying closer to home I'd recomend:
http://chandoo.org/wp/2011/12/21/formula-forensics-no-007/
http://chandoo.org/wp/2011/05/26/advanced-sumproduct-queries/