$hash_ref -> { key1 } = "new value1";
$hash_ref -> { key3 } = "add value3";
$hash_ref -> { ary1 }[2] = { ary_key21 => "ary_value21", ary_key22 => "ary_value22", };

use Data::Dumper;
print Dumper($hash_ref);
exit;