"--" operator in a formula

[Arla M]

I tried looking under Excel's help, but it did not produce any results.
In another question, I was given a SUMPRODUCT formula which had "--" < those
2 characters before my range.

Can someone tell me what the significance of the characters in the formula
are? Or point me to a website that explains?

I feel much more comfortable when I completely understand the formula I am
writing.

Thank you!

 

[Max]

Try the 2* responses in this previous post:

http://tinyurl.com/64py9

*Bob Phillips' link to his page, and
Jason's example and explanation, with a nice touch on its evolution

 

[Max]

See also JE McGimpsey's:
http://www.mcgimpsey.com/excel/formulae/doubleneg.html