How do I move an array element with a known key to the end of an array in PHP?

The only way I can think to do this is to remove it then add it:

$v = $my_array['monkey'];
unset($my_array['monkey']);
$my_array['monkey'] = $v;

array_shift is probably less efficient than unsetting the index, but it works:

$my_array = array('monkey' => 1, 'giraffe' => 2, 'lion' => 3);
$my_array['monkey'] = array_shift($my_array);
print_r($my_array);

Another alternative is with a callback and uksort:

uksort($my_array, create_function('$x,$y','return ($y === "monkey") ? -1 : 1;'));

You will want to use a proper lambda if you are using PHP5.3+ or just define the function as a global function regularly.

I really like @Gordon's answer above for it's elegance as a one liner, but it only works if the key is at the beginning. Here's another one liner that will work for a key in any position:

$arr = array('monkey' => 1, 'giraffe' => 2, 'lion' => 3);
$arr += array_splice($arr,array_search('giraffe',array_keys($arr)),1);

EDIT: Beware, this fails with numeric keys.