DB<116> use warnings; $a=undef; print "< @{$a} >" Use of uninitialized value in array dereference at (eval 49)[multi_perl5db.pl:644] line 2. < > DB<117> use warnings; $a=[]; print "< @{$a} >" < > DB<118> use warnings; $a=undef//[]; print "< @{$a} >" < > DB<120> use warnings; $a=[1..3]//[]; print "< @{$a} >" < 1 2 3 >