Hi I run across below formula and I do not understand what does SUMPRODUCT and why using (--( why a double -- means, can somebody explain the logic?


=AP6+SUMPRODUCT(--('Data-WW Summary'!$D$8:$D$5000='RSM Summary'!$C6)*--('Data-WW Summary'!$E$8:$E$5000='RSM Summary'!$B6),--('Data-WW Summary'!$CB$8:$CB$5000))