On Tue, 10 Jul 2007 11:32:54 -0700 (PDT)
Vincent Li <[EMAIL PROTECTED]> wrote:
>
> I am trying to experiment a simple perl math caculation script I wrote:
>
> #!/usr/bin/perl
> use strict;
> use warnings;
>
> my %operator = (
> minus => '-',
> add => '+',
> multiply => '*',
> divide => '/',
> );
>
> my $big = 5;
> my $small = 2;
>
> for (values %operator) {
>
> my $result = $big $_ $small;
>
> print "$result\n";
>
> }
>
> I know the "my $result = $big $_ $small" is not valid perl expression,and
> may look stupid :) but you get the idea that I want to achieve that
> because the operator is stored in a varible and unknown to me. I guess
> there is other way around, I am just not aware of.
>
> Thanks in advance
>
> Vincent
>
you could also do:
my %operator = (
minus => sub { return $_[0] - $_[1] },
add => sub { return $_[0] + $_[1] },
multiply => sub { return $_[0] / $_[1] },
divide => sub { return $_[0] * $_[1] },
);
foreach (values %operator) {
my $result = &{$_}($big,$small);
print $result;
}
thats a different concept, but usually you want to avoid eval, since you could
open a door for code injection.
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
http://learn.perl.org/
