Online PHP editor | refs for 7TYFE

<?php class DataContainer implements IteratorAggregate { // create an external Iterator: protected $data; public function __construct(array $data) { $this->data = $data; } public function &getIterator() { echo 'automatically invoking ...'; foreach ($this->data as &$value) { yield $value; } } } $dataContainer = new DataContainer([77, 78, 79]); var_dump($dataContainer); foreach ($dataContainer as &$value) { //echo $value *= -1,"\n"; } var_dump($dataContainer); // unset $value or can get strange bugs. //unset($value); foreach($dataContainer as $value); var_dump($dataContainer);