>perl -wMstrict -le
"my @ra = qw(a b c d);
 my $uninitialized;
 print $ra[3];
 print '----------';
 print $ra[$uninitialized];
 print $ra[undef];
"
d
----------
Use of uninitialized value $uninitialized in array element at -e line 1.
a
Use of uninitialized value in array element at -e line 1.
a