$ perl -Mwarnings -Mstrict -MData::Dumper -E'
my @foo = ( [qw/ a b c /], undef );
say "@$_" for @foo;
'
a b c
Can't use an undefined value as an ARRAY reference at -e line 3.

##</code><code>##

$ perl -Mwarnings -Mstrict -MData::Dumper -E'
my @foo = ( [qw/ a b c /], undef );
say "@{ $_ // [] }" for @foo;
'
a b c