perl -Mstrict -le 'my %s=(foo => "bar"); print "%s"'
%s

perl -Mstrict -le 'my $s=[qw/foo bar/]; print "%$s%"'
%ARRAY(0x1801380)%

perl -Mstrict -le 'my $s=[qw/foo bar/]; print "@$s@"'
foo bar@