Rotate an array of arrays clockwise 90 degrees

Question

I would like to rotate the orientation of an array so that rows and columns are inverted.

For example, I want to convert this:

1     cat     calico
2     dog     collie
3     cat     siamese
4     dog     mutt

to this:

4       3        2         1
dog     cat      dog       cat
mutt    siamese  collie    calico

How can I accomplish this?

Answer 1

Here is a way you can accomplish this:

function rotate_2d_array($array)
{
    $result = array();
    foreach (array_values($array) as $key => $sub_array)
    {
        foreach (array_values($sub_array) as $sub_key => $value)
        {
            if (empty($result[$sub_key]))
            {
                $result[$sub_key] = array($value);
            }
            else
            {
                array_unshift($result[$sub_key], $value);
            }
        }
    }
    return $result;
}

And here is the test:

$a = array(
    array(1, 'cat','calico'),
    array(2, 'dog', 'collie'),
    array(3, 'cat', 'siamese'),
    array(4, 'dog', 'mutt')
);
print_r($a);

$b = rotate_2d_array($a);
print_r($b);