use v5.30;
use strict;
use warnings;

{
  my $add = 0;
  sub getter { $add }
  
  sub counter {
    my @nums = (1..500);
    for my $num (@nums) { $add += $num; }
  }
}

counter();
say "getter => ", getter();

##</code><code>##

use v5.30;
use strict;
use warnings;

sub counter {
  my $add = 0;
  my @nums = (1..500);
  for my $num (@nums) { $add += $num; }
  return $add;
}

my $got = counter();
say "got => ", $got;

##</code><code>##

{
  my $foo = 123;
  sub myfunc {
    ...;
  }
}

##</code><code>##

sub myfunc {
  state $foo = 123;
  ...;
}

##</code><code>##

{
  my $foo;
  sub myfunc {
    $foo ||= 123;
    ...;
  }
}