What does "--" mean?

... in the formula: =SUMPRODUCT(--(A2:A7>0),--(A2:A7<11)) ?

http://answers.microsoft.com/en-us/o...9-64b26f137c94

An array function like (A2:A7>0) returns a series of TRUE and FALSE values. If you carry out simple arithmetic on these, like adding zero or multiplying by 1, this will convert those logical values to 1's and 0's, which can then be added together. The double unary minus (--) effectively multiplies the array by -1 twice, and thus coerces the logical TRUE/FALSE values to 1/0.

Hope this helps.

Pete

Ok. Thanks.