$myArrays = array(
    array(1, 2, 3, 4),
    array(5, 6, 7, 8),
    array(9, 10, 11, 12),
    array(13, 14, 15, 16)
);

<?php
$myArrays = array(
    array(1, 2, 3, 4),
    array(5, 6, 7, 8),
    array(9, 10, 11, 12),
    array(13, 14, 15, 16)
);

$counter1 = 0;

while($counter1 < 4)
{
    echo $myArrays[$counter1][0];
    echo "n";
    $counter1++;
    }

    $counter1 = 3;

    while($counter1 >= 0)
    {
        echo $myArrays[$counter1][1];
        echo "n";
        $counter1--;
    }

    $counter1 = 0;

    while($counter1 < 4)
    {
        echo $myArrays[$counter1][2];
        echo "n";
        $counter1++;
    }

    $counter1 = 3;

    while($counter1 >= 0)
    {
        echo $myArrays[$counter1][3];
        echo "n";
        $counter1--;
    }
    ?>