<?php

$array = array('koala', 'kangaroo', 'wombat', 'wallaby', 'emu', 'kiwi', 'kookaburra', 'platypus');
/*** create the array object ***/
$arrayObj = new ArrayObject($array);
/*append a new value in the array*/
$arrayObj->append('dingo');
/*Sort a arrayobject */
$arrayObj->natcasesort();
/*Get the iterator obj*/
$iterator = $arrayObj->getIterator();
$arrayObj->offsetUnset(5);
if ($arrayObj->offsetExists(4)) {
    echo "Offset exitst" . "<br>";
}
/*Count the total array*/
echo "Total amount of " . $arrayObj->count() . "<br>";
/*Get traverse the whole the array*/
while ($iterator->valid()) {
    echo $iterator->key() . ' => ' . $iterator->current() . '<br />';
    $iterator->next();
}
<?php

//重点是演示ArrayObject中的natcasesort()方法
$array = array('koala', 'kangaroo', 'wombat', 'wallaby', 'emu', 'kiwi', 'kookaburra', 'platypeus');
$array_obj = new ArrayObject($array);
$array_obj->natcasesort();
for ($iterator = $array_obj->getIterator(); $iterator->valid(); $iterator->next()) {
    echo $iterator->key(), "=>", $iterator->current(), "\n";
}
 public function natcasesort()
 {
     $this->lazyLoadArray();
     parent::natcasesort();
 }
<?php

/* Prototype  : int ArrayObject::natcasesort()
 * Description: proto int ArrayIterator::natcasesort()
 Sort the entries by values using case insensitive "natural order" algorithm. 
 * Source code: ext/spl/spl_array.c
 * Alias to functions: 
 */
echo "*** Testing ArrayObject::natcasesort() : basic functionality ***\n";
$ao1 = new ArrayObject(array('boo10', 'boo1', 'boo2', 'boo22', 'BOO5'));
$ao2 = new ArrayObject(array('a' => 'boo10', 'b' => 'boo1', 'c' => 'boo2', 'd' => 'boo22', 'e' => 'BOO5'));
var_dump($ao1->natcasesort());
var_dump($ao1);
var_dump($ao2->natcasesort('blah'));
var_dump($ao2);
?>
===DONE===
 /**
  * Implementation of ArrayObject::natcasesort().
  *
  * This method is a case insensitive version of ArrayObject::natsort.
  *
  * This method implements a sort algorithm that orders alphanumeric strings
  * in the way a human being would while maintaining key/value associations.
  * This is described as a "natural ordering".
  *
  * No value is returned.
  */
 public function natcasesort()
 {
     $this->arrayObject->natcasesort();
 }