"my" variable $x masks earlier declaration in same scope at 585826.pl line 4.
"my" variable $x masks earlier declaration in same scope at 585826.pl line 6.
print __LINE__ . ": " . \$x . " = $x \n";
my $x = 123;
print __LINE__ . ": " . \$x . " = $x \n";
my $x = 456;
print __LINE__ . ": " . \$x . " = $x \n";
my $x;
print __LINE__ . ": " . \$x . " = $x \n";