2010/4/13 Magne Sandøy <msan...@gmail.com>:
> Thanks for all the good info. I think I have a grasp on incrementing and
> comparison, but now, what puzzles me, is the fact that when I use "le" less
> than or equal, why does it actually increment the "z"? It is by then passed
> the less than, and already at equal to "z". It should then just exit the
> loop.
> And just to add to my confusion, "ge" and "gt" does not give any output at
> all. "u" is not greatier than "z", is it?
IIRC, you're referring to this loop (from the OP):
> for ($_="u"; $_ le "z"; $_++){
> print " $_ ";
> }
Note that in for loops, the 'increment' (i.e., $_++) occurs before the
condition ($_ le "z"). So when $_ is equal to "z", the condition
passes (i.e., $_ is less than or /equal/ to "z"). Then $_ is
"incremented" from "z" to "aa". This too is /less than/ or equal to
"z" using a string comparison so it continues on until it reaches
"za", which is not.
You may be thinking of lt instead of le. If you used lt then when $_
was "z" it would fail the << $_ lt "z" >> condition and exit out of
the loop right there. Because you're using le instead, you enable the
string ordering to "wrap" back around to "aa", which starts a long
process of "increments" before reaching something not less than or
equal to the string "z".
The reason gt and ge won't give any output at all is because $_ starts
at "u", which is not greater than /nor/ equal to "z" so the condition
fails right away.
Forgive me if I'm misread you.
--
Brandon McCaig <bamcc...@gmail.com>
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