I read through the suggestions below and they are great ones!
To summarize:
a)everything in Perl is a string until used in a numeric context.
b)Never, ever compare float values for equality in any languag!
c)If you compare $num1 < $num2 and both $num1 and $num2 can be converted to a number, then is is fine! If that is not true, then that's a problem.
I present here one of my subs that can compare text or numbers. This is not "perfect" and there are problems with say the "-" sign, but is a general idea.
sub alpha_num_cmp {
my($a, $b) = @_;
if (( $a =~ m/\D/) || ($b =~ m/\D/)) { #look for a non-digit
return ($a cmp $b); #if so, then use string compare
}
return ($a <=> $b); #otherwise straight numeric comparison
}