Getting an array from one property of an associative array best practice

Question

I have an array of objects eg.

[ array( 'id' => 1, 'name' => "simon" ), ... ]

and I need to get an array of IDs eg. [1,2,3,4,5];

Currently I'm doing this:

 $entities = $this->works_order_model->get_assigned_entities($id);
 $employee_ids = array();
 foreach ($entities as $entity) {
 array_push($employee_ids, $entity->id);
 } 

Is there a best practice way of doing this?

Answer 1

I think array_map is what you are looking for:

php > $aa = array (array ("id" => 1, "name" => 'what'), array('id' => 2));
php > function id($i) { return $i['id'];};
php > print_r(array_map ('id', $aa));
Array
(
 [0] => 1
 [1] => 2
)

• JordanC: Thanks for this. Is the function id() necessary? I don't see it being used.
• kasterma: It is used as the first argument to array_map (the first argument is a string that is the name of a function to use).