use Data::Dumper;
%foo=(BAZ=>1);
print Dumper \%foo if $foo{BAR} || 1;
print Dumper \%foo if @foo{BAR,BAZ} || 1;

##</code><code>##

use Data::Dumper;
%foo=(BAZ=>1);
print Dumper \%foo if call($foo{BAR});
print Dumper \%foo if call(@foo{BAR,BAZ});
sub call { return 1 }