<?php
// Array of available fruits
$fruits = array("lemons" => 1, "oranges" => 4, "bananas" => 5, "apples" => 10);
// Array of locations in Europe
$locations = array('Amsterdam', 'Paris', 'London');
$fruitsArrayObject = new ArrayObject($fruits);
// Now exchange fruits for locations
$old = $fruitsArrayObject->exchangeArray($locations);
var_dump($old);
var_dump($fruitsArrayObject);
?>
     
    The above example will output:
array(4) {
  ["lemons"]=>
  int(1)
  ["oranges"]=>
  int(4)
  ["bananas"]=>
  int(5)
  ["apples"]=>
  int(10)
}
object(ArrayObject)#1 (1) {
  ["storage":"ArrayObject":private]=>
  array(3) {
    [0]=>
    string(9) "Amsterdam"
    [1]=>
    string(5) "Paris"
    [2]=>
    string(6) "London"
  }
}