=IF(B1,"",SUMPRODUCT(--(B$1:B$5=""),--(A1<A$1:A$5))+1), Biff formula

[Rasoul Khoshravan]

In a solution posted by Biff on Oct 24, 3:18AM, subjected "Vlookup formula
criteria" in a reply to gmunro question, Biff used an IF function with
following structure:
=IF(B1,"",SUMPRODUCT(--(B$1:B$5=""),--(A1<A$1:A$5))+1)
I thought in an If function the first part should show the condition,
second: action if the outcome is true and third is the action if outcome is
false.
Here the condition is only B1, so what is the condition?

 

[Guest]

It would help to know what data was expected to be in B1, but I'm too lazy to
search for the question in question. However, as a test, I tried the
following (don't know how it will look after the paste.) :

TRUE y
FALSE n
abc #VALUE!
n
1 y
0 n
-1 y
#N/A #N/A
10/24/2006 y
4 y

I put true in A1, false in A2, also used blank, positive & negative #, 0,
error, a date and formula. Then used a formula in corresponding cell in B of
=IF(A1,"y","n")
As can be seen, true, positive or negative number, date, and formula (at
least one that returns 4) returns a y. I don't know if that helps, but there
you go.