Hi All

Quite often when trailing through the posts I come across the above, I have spent time on the internet looking for an explanation with no success so would appreciate if someone with the knowledge could explain when you would use "--" and why? I am familiar with Sumproduct but the double dash has me stumped.

This is the most recent sample I saw =SUMPRODUCT(--(MOD($A$1:$A$19,2)=0)) for counting even numbers.

Thanks

George