what does it mean (--) in sumproduct formula

[learning_grexcel]

I'm just learning sumproduct from different free online sources. I notice that the following two formulas produce same result.

I wonder if there is any difference between them and what occasions we put (--) usually.



= sumproduct((D1:D5) * (B1:B5 = "x") * (C1:C5 = "123"))


=sumproduct (--(B1:B5="x"), --(C1:C5="123"), (D1:D5))

 

[VoG]

-- coerces an array of False/True to an array of 0/1 that sumproduct can evaluate. Using -- is more efficient than *

 

[Andrew Poulsom]

The -- coerces TRUE/FALSE into 1/0 so that SUMPRODUCT can do its multiplication.

 

[ewilsonlds]

Whenever you put -- in the front of the parenthesis, it changes all of the True values in the parenthesis to the value 1.

 

[Robert Mika]

More information:
http://www.xldynamic.com/source/xld.SUMPRODUCT.html

 

[pgc01]

I'm just learning sumproduct from different free online sources. I notice that the following two formulas produce same result.

I wonder if there is any difference between them and what occasions we put (--) usually.



= sumproduct((D1:D5) * (B1:B5 = "x") * (C1:C5 = "123"))


=sumproduct (--(B1:B5="x"), --(C1:C5="123"), (D1:D5))

In your example they will give different results if you have a non-numeric value in column D.

For ex., assume that you write prices for articles in column D. If you write "No longer in catalog" in D3, the first formula will error out while the second one will simply ignore that value.

 

[learning_grexcel]

Thanks to all

I got it now