SUM for logical values

[Guest]

Using Excel 2002 SP3...

If I type logical values into the formula, like this: =SUM(TRUE, TRUE,
TRUE), my formula returns the value 3.
If I reference cells containing logical values, like this =SUM(A1:A3), my
formula returns 0.
Does anybody know why there is a difference?

 

[Ragdyer]

Try:

=A1+A2+A3

 

[Peo Sjoblom]

Try

=SUMPRODUCT(--(A1:A3))

or array enter (ctrl + shift & enter)

=SUM(--(A1:A3))

 

[Guest]

Thanks, to both of you...

I understand the alternatives.I've been using something like this:
=COUNTIF(A1:A3,TRUE)

I guess I was asking if there is a programming rationale as to why Excel is
treating literal logical values differently than cell references when the
cells contain logical values.

 

[Jerry W. Lewis]

SUM does not coerce non-numeric data types in ranges, but does coerce
them in constants. In addition to boolean values, =SUM("1","2") returns
3 and =SUM("1","2","Fred") returns #VALUE while =SUM(A1:A3) returns 0
with the corresponding values in that range.

But that is more a "what" than a "why". Best I can do on why is that it
is a design decision. I would not have designed it that way, but then I
didn't design it. On the other hand, I am glad that someone did design
it, and living with some design decisions that I wouldn't have made is
the price of using it.

Jerry

 

[R.VENKATARAMAN]

this is what I have read in these newsgroups

suppose C1 to C8 are (logical values due to a question of two cells being
equal)

FALSE
FALSE
FALSE
FALSE
TRUE
TRUE
TRUE
TRUE
in an empty cell
=SUMPRODUCT(C1:C8*C1:C8)
gives 4

 

[Guest]

I agree with you - I'm glad someone designed it. I'm still curious.