OpenEuphoria

Re: evaluation of if statement

• Posted by munchr at mac.com Mar 17, 2002
• 373 views

At 06:10 PM 17/03/2002 -0800, I wrote:
>I can't seem to get the following code to work.  Should this work like
>I expect it to, or does it need to be rewritten?
>
>Ideally, given a sequence of {1,2,3} it should evaluate false, but
>given {'b',2,3}, or {'b','B','b'} it should process true when
>"position" corresponds to the position of the letter in the sequence.
>But it always processes as false, even when the sequence element
>has an ascii value between 'Z' and 'A'.
>
>for position = 1 to length(input) do
>    if 'Z' >= upper(input[position]) >= 'A' then
>       found = find(upper(input[position]), upper(mapping))
>    else
>       found = find(input[position], mapping)
>    end if
>end for

I changed the order of the if statement to
      if 'A' <= upper(input[position]) <= 'Z' then
and now it seems to work fine.

Any explanation why simply changing the order of 'A' and 'Z'
with the corresponding change to the >= evaluations would
change the outcome?  From what I can tell, the two lines are
functionally equivalent and should both work.
    if 'Z' >= upper(input[position]) >= 'A' then -- won't work
if 'Z' is greater than/equal to variable is greater than/equal to 'A'
    if 'A' <= upper(input[position]) <= 'Z' then -- works
if 'A' is less than/equal to variable is less than/equal to 'Z'

Am I wrong about this?

James Powell
Now I'm really confused