>perl -wMstrict -le
"my @Array = ('A', undef, 'B', '0', 'C', 0);
 print join ' ', map {qq(\"$_\")} grep { $_ } @Array;
"
"A" "B" "C"

##</code><code>##

>perl -wMstrict -le
"my @Array = ('A', undef, 'B', '0', 'C', 0);
 print join ' ', map {qq(\"$_\")} grep { length } @Array;
"
Use of uninitialized value in length at -e line 1.
"A" "B" "0" "C" "0"

##</code><code>##

>perl -wMstrict -le
"my @Array = ('A', undef, 'B', '0', 'C', 0);
 print join ' ', map {qq(\"$_\")} grep {defined and length} @Array;
"
"A" "B" "0" "C" "0"