Hi everyone

I've got these three sumproduct formulas that returns the right answer.
=SUMPRODUCT((YEAR(A5:A150)=2008)*(C5:C150="Dept021 ")*B5:B150)
=SUMPRODUCT(--(YEAR(A5:A150)=2008),--(C5:C150="Dept021"),B5:B150)
=SUMPRODUCT(N(YEAR(A5:A150)=2008),N(C5:C150="Dept0 21"),B5:B150)
I would like to know if they're all the same.
Can they be use for different situation.
Any preference over others and for what reason?

Thank you
Regards
John