The difference between "% p" and "my% p"?

Question

% %p = ('option1' => 'Option 1', 
% 'option2' => 'Option 2', 
% 'option3' => 'Option 3'
% );
    <select name="killer_feature" id="killer_feature" class="select">
% foreach (keys %p) {
% my $selected = param('killer_feature') && param('killer_feature') eq $_ ? 'selected="selected"' : '';
% if (!param('killer_feature') && $_ eq 'option2') { $selected = 'selected="selected"' }
    <option value=" <%=$_%>" <%= $selected %>>
        <%= $p{$_} %>
    </option>
% }
    </select>

the above code breaks the application by returning "Internal server error", but if I smiply edit the very first line before % my %p(I tried this because some other controls have this format), it works, I wonder what the difference is between them.

His perl application is built on the Mojolicious web framework.

Many thanks!

Answer 1

Raw %p , () "% p". , - . %main::p, .

Perl pragma use strict ( mojo), , , %p , .

my "% p" () , strict.

( ) Perl - Randal Schwartz Stonehendge: http://www.stonehenge.com/merlyn/UnixReview/col46.html

Answer 2

, :, my ?

my , :

#!/usr/bin/perl

use strict;

   my $foo = "defined in outer";
   print_result ("outer",$foo);             # outer: defined in outer

   {
      # $foo has not yet been defined locally
      print_result ("inner",$foo);          # inner: defined in outer

      my $foo = "defined in inner";         # defining $foo locally

      print_result ("inner",$foo);          # inner: defined in inner 

      my $foo;                              # re-declaring $foo

      print_result ("inner", $foo);         # inner:  
   } 

   # even though $foo was defined in the subroutine, it did not
   # override the $foo outside the subroutine (localization occured)
   print_result ("outer",$foo);             # main: defined in main      


   sub print_result {
      my ($proc,$value) = @_;
      print qq{$proc:\t$value\n};
   }

Mojolicious use strict, , (my, our, local ..).

, , my . , .

, , .