// Creating a multidimensional array
$matrix = array(
    array(1, 2, 3),
    array(4, 5, 6),
    array(7, 8, 9)
);

// Accessing elements in a two-dimensional array
echo $matrix[0][1]; // Outputs 2
echo $matrix[1][2]; // Outputs 6
echo $matrix[2][0]; // Outputs 7