Sort an Array by keys based on another Array?

Question

Just use array_merge or array_replace. array_merge works by starting with the array you give it (in the proper order) and overwriting/adding the keys with data from your actual array:

$customer['address']    = '123 fake st';
$customer['name']       = 'Tim';
$customer['dob']        = '12/08/1986';
$customer['dontSortMe'] = 'this value doesnt need to be sorted';

$properOrderedArray = array_merge(array_flip(array('name', 'dob', 'address')), $customer);
// or
$properOrderedArray = array_replace(array_flip(array('name', 'dob', 'address')), $customer);

// $properOrderedArray: array(
//   'name'       => 'Tim',
//   'dob'        => '12/08/1986',
//   'address'    => '123 fake st',
//   'dontSortMe' => 'this value doesnt need to be sorted')

PS: I'm answering this 'stale' question, because I think all the loops given as previous answers are overkill.

There you go:

function sortArrayByArray(array $array, array $orderArray) {
    $ordered = array();
    foreach ($orderArray as $key) {
        if (array_key_exists($key, $array)) {
            $ordered[$key] = $array[$key];
            unset($array[$key]);
        }
    }
    return $ordered + $array;
}

How about this solution

$order = array(1,5,2,4,3,6);

$array = array(
    1 => 'one',
    2 => 'two',
    3 => 'three',
    4 => 'four',
    5 => 'five',
    6 => 'six'
);

uksort($array, function($key1, $key2) use ($order) {
    return (array_search($key1, $order) > array_search($key2, $order));
});

Another way for PHP >= 5.3.0:

$customer['address'] = '123 fake st';
$customer['name'] = 'Tim';
$customer['dob'] = '12/08/1986';
$customer['dontSortMe'] = 'this value doesnt need to be sorted';

$customerSorted = array_replace(array_flip(array('name', 'dob', 'address')), $customer);

Result:

Array (
  [name] => Tim
  [dob] => 12/08/1986
  [address] => 123 fake st
  [dontSortMe] => this value doesnt need to be sorted
)

Works fine with string and numeric keys.

function sortArrayByArray(array $toSort, array $sortByValuesAsKeys)
{
    $commonKeysInOrder = array_intersect_key(array_flip($sortByValuesAsKeys), $toSort);
    $commonKeysWithValue = array_intersect_key($toSort, $commonKeysInOrder);
    $sorted = array_merge($commonKeysInOrder, $commonKeysWithValue);
    return $sorted;
}

Take one array as your order:

$order = array('north', 'east', 'south', 'west');

You can sort another array based on values using array_intersect^­Docs:

/* sort by value: */
$array = array('south', 'west', 'north');
$sorted = array_intersect($order, $array);
print_r($sorted);

Or in your case, to sort by keys, use array_intersect_key^­Docs:

/* sort by key: */
$array = array_flip($array);
$sorted = array_intersect_key(array_flip($order), $array);
print_r($sorted);

Both functions will keep the order of the first parameter and will only return the values (or keys) from the second array.

So for these two standard cases you don't need to write a function on your own to perform the sorting/re-arranging.

I used the Darkwaltz4's solution but used array_fill_keys instead of array_flip, to fill with NULL if a key is not set in $array.

$properOrderedArray = array_replace(array_fill_keys($keys, null), $array);