>perl -we"my $x; my $q = eval { $x / 4 } || 0;
Use of uninitialized value in division (/) at -e line 1.

>perl -we"my $x; my $q = eval { ($x||0) / 4 };

>perl -we"my $x; my $q = ( $x / 4 ) || 0;
Use of uninitialized value in division (/) at -e line 1.

>perl -we"my $x; my $q = ( ($x||0) / 4 );