PHP Short arrays based on sub-object value - php

Question

I have an array where contains simple objects. The array I have looks like the following:
[posts] => Array
(
[0] => WP_Post Object
(
[ID] => 4
[post_title] => Post #4
...
)
[1] => WP_Post Object
(
[ID] => 100
[post_title] => Post #100
...
)
[2] => WP_Post Object
(
[ID] => 1
[post_title] => Post #1
...
)
[3] => WP_Post Object
(
[ID] => 21
[post_title] => Post #21
...
)
)
also I have an array that contains the first array posts ID in the order I like to show that posts. Lets say that the array map likes like that:
[map] => Array
(
[0] => 4
[1] => 21
[2] => 100
[3] => 1
)
Now the quation. Can I order the array that contains the objects, based on each object ID Property by using as a map the Map array, in order to have a result that will look like this:
[posts] => Array
(
[0] => WP_Post Object
(
[ID] => 4
[post_title] => Post #4
...
)
[1] => WP_Post Object
(
[ID] => 21
[post_title] => Post #21
...
)
[2] => WP_Post Object
(
[ID] => 100
[post_title] => Post #100
...
)
[3] => WP_Post Object
(
[ID] => 1
[post_title] => Post #1
...
)
)

Answer 1

PHP has a builtin way to do this, using the array_multisort function:
$col = array();
foreach ($posts as $post) {
$col[] = array_search($post->ID, $map);
}
array_multisort($col, $posts);
// now $posts is sorted in the order specified in $map
Try it here: http://codepad.org/5rqncj3B

Answer 2

My solution maybe isn't efficient, but it's simple:
function find_post_by_id($posts, $id) {
foreach($posts as $post) {
if ($post->id == $id) {
return $post;
}
}
// error handling here
}
$sorted_posts = array();
foreach($map as $id) {
$sorted_posts[] = find_post_by_id($posts, $id);
}