my %control = map { $_ => 'false' } split ' ', 'play ctrl loop'
my %control = map { $_ => 'true' } split ' ', $4;

##</code><code>##

$control{$_} = 'true' foreach split ' ', $4;

##</code><code>##

foreach ( split ' ', $4 ) {
    $control{$_} = 'true';
}