$ perl -wE'
my $aref = [ { name => 'Fred' }, { name => 'Barney' }, { no_name => 'Wilma' } ];
say for map { $_->{name} } @{ $aref };
'
Fred
Barney
Use of uninitialized value $_ in say at -e line 3.


##</code><code>##

$ perl -wE'
my $aref = [ { name => 'Fred' }, { name => 'Barney' }, { no_name => 'Wilma' } ];
say for map { $_->{name} || 'No name' } @{ $aref };
'
Fred
Barney
No name