Sumproduct(--

[forestview]

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

[WasWodge]

It is a double unary operator to convert true and false to 1 an 0 respectively. See Format of Sumproduct in the link below.

http://www.xldynamic.com/source/xld....CT.html#format

[Jacc]

Sumproduct don't like True and False. -- Converts it into 1 and 0. Multiplying by 1 does the same thing but I guess -- is quicker.

[forestview]

Hi WasWodge your link is very informative and a great help.

Thanks to all who responded.



"Education is the salvation of Ignorance"

[snb]

=-1 turns 1 into -1
=--1 turns 1 into 1

=+False results in False
=+True results in True

=-False results in 0
=--False results in 0
=-True results in -1
=--True results in 1

=N(True) results in 1
=N(False) results in 0

=1*False results in 0
=1*True results in 1

=False/1 result in 0
=True/1 tesults in 1

=false^1 results in 0
=True^1 results in 1

If you want the result 0 if false and 1 if true, you can use
= --(condition)
= N(condition)
=1*(condition)
etc.

[forestview]

Hi SNB

Nice one I understand it all by relating it to Boolean algebra its all logic

Thanks