note 125944 added to class.arrayiterator

I recommend using ArrayIterator() only in the IteratorAggregate interface on behalf of memory usage. When not used in that context, the array will be copied on creating a new ArrayIterator(). <?php class Data implements IteratorAggregate { private array $array = []; public function __construct() { for ($i = 0; $i < 1e5; $i++) $this->array[] = true; } public function getIterator(): ArrayIterator { return new ArrayIterator($this->array); } } $data1 = new Data(); echo memory_get_usage(), PHP_EOL; // 4610240 foreach($data1 as $data) {} echo memory_get_usage(), PHP_EOL; // 4610240 foreach($data1 as $data) {} echo memory_get_usage(), PHP_EOL; // 4610240 ?> Memory usage still stay the same. Now create it without the IteratorAggregate interface. <?php $agg = []; for ($i = 0; $i < 1e5; $i++) $agg[] = true; echo memory_get_usage(), PHP_EOL; // 8808720 $iterator1 = new ArrayIterator($agg); echo memory_get_usage(), PHP_EOL; // 13007328 $iterator2 = new ArrayIterator($agg); echo memory_get_usage(), PHP_EOL; // 17205936 ?> ---- Server IP: 45.112.84.4 Probable Submitter: 45.112.85.246 (proxied: 2003:ed:8f12:5e39:d11:cc02:c2e8:1d8f) ---- Manual Page -- http://php.net/manual/en/class.arrayiterator.php Edit -- https://master.php.net/note/edit/125944 Del: integrated -- https://master.php.net/note/delete/125944/integrated Del: useless -- https://master.php.net/note/delete/125944/useless Del: bad code -- https://master.php.net/note/delete/125944/bad+code Del: spam -- https://master.php.net/note/delete/125944/spam Del: non-english -- https://master.php.net/note/delete/125944/non-english Del: in docs -- https://master.php.net/note/delete/125944/in+docs Del: other reasons-- https://master.php.net/note/delete/125944 Reject -- https://master.php.net/note/reject/125944 Search -- https://master.php.net/manage/user-notes.php