=Trim() will return a string (not a number). (Same with =right(), =left(),
=mid()).

So if you had 1234ASDF in a cell and wanted to extract the character 1, you
could use:

=left(a1,1)
But this formula returns the string '1 (like entering a value with a leading
apostrophe).

One way to convert that string 1 to a number 1 is to multiply by 1.
=left(a1,1)*1
or add 0
=left(a1,1)+0

Or even using --
=--left(a1,1)
The rightmost minus would convert it to -1 and the left minus would change the
sign back to positive.

===
You may have seen this in formulas like:

=sumproduct(--(a1:a10="hi"),--(b1:b10="there"))

In this case, the right minus converts True/Falses to -1/0's and the left minus
converts the -1/0 to +1/0.

(and sumproduct likes to work with numbers--not true/false's.)



Ted Metro wrote:

Sometimes I'll see a dash-dash used in a formula like -

--trim
or
--left

What does that double-dash do when it's infront of the function, and why use
'--trim' instead of just 'trim'?

Ted

--

Dave Peterson