use Devel::Peek;

my @z;
$a = \$z[1];
say "\$z[$_] exists: ", exists( $z[$_] ) || 0 for 0..2;

say '---Dump @z';
Dump @z;

say '---Dump $z[0]';
Dump $z[0];

say '---Dump $z[1]';
Dump $z[1];