for my $name (keys %characters) {
  my $id = $name;
     $id =~ s! !_!g;
     $id =~ s![^-\w:.]!!g; 
  
  my $experience = $characters{$name}{experience};
  my @classes = @{$characters{$name}{classes}};

##</code><code>##

use strict;
use warnings;
use 5.010;

my @classes = ('A', 'B');

for (1 .. 3) {
    my @classes = ('C', 'D');
    say "@classes";
}

say "\n@classes";

--output:--
C D
C D
C D

A B