@args = ( qw/fee fie foe fum/, func_that_returns_undef_for_error(), 1..3 );

##</code><code>##

sub string_maybe_undef {
   $_ ? $_ : ''
}

##</code><code>##

print string_maybe_undef($_).": '".string_maybe_undef($_[$_])."'\n" foreach  0..$#_;