Path coverage

        $h = 0;
        if ($x)
        {
            $h = { a => 1 };
        }
        if ($y)
        {
            print $h->{a};
        }

• Four paths through this code

        $x   $y

         0    0
         0    1
         1    0
         1    1

• For 100% path coverage all four must be taken

• Missing elses count as paths