Using objects with array_fill may cause unexpected results. Consider the following:

<?php
class Foo {
   public $bar = "banana";
}

//fill an array with objects
$array = array_fill(0, 2, new Foo());

var_dump($array);
/*
array(2) {
  [0]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(6) "banana"
  }
  [1]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(6) "banana"
  }
} */

//now we change the attribute of the object stored in index 0
//this actually changes the attribute for EACH object in the ENTIRE array
$array[0]->bar = "apple";

var_dump($array);
/*
array(2) {
  [0]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(5) "apple"
  }
  [1]=>
  object(Foo)#1 (1) {
    ["bar"]=>
    string(5) "apple"
  }
}
 */
?>

Objects are filled in the array BY REFERENCE. They are not copied for each element in the array.