Online PHP editor | output for EP0fL

<?php class IndexedArrayIterator implements Iterator { protected $data=array(); protected $keyIndex=array(); protected $reverseIndex=array(); protected $position=0; protected $startIndex=0; protected $endIndex=0; function __construct($source) { $this->data=$source; $this->reindex(); } function reindex() { // Reindexing is expensive, don't do it often // If you need to reindex every time you search, you loose the advantage // If you add elements, you must reindex $this->keyIndex = array_keys($this->data); $this->reverseIndex = array_flip($this->keyIndex); } function setStartKey($start) { $this->startIndex=$this->reverseIndex[$start]; } function setEndKey($end) { $this->endIndex=$this->reverseIndex[$end]; } ///// /// Iterator Interface // #[\ReturnTypeWillChange] public function rewind() { $this->position=$this->startIndex; } #[\ReturnTypeWillChange] public function current() { if($this->valid()) return $this->data[$this->key()]; else return NULL; } #[\ReturnTypeWillChange] public function key() { if($this->valid()) return $this->keyIndex[$this->position]; else return NULL; } #[\ReturnTypeWillChange] public function next() { ++$this->position; } #[\ReturnTypeWillChange] public function valid() { if($this->position > $this->endIndex) return FALSE; return isset($this->keyIndex[$this->position]); } } $iterator=new IndexedArrayIterator(array( 'one'=>'Item One', 'two'=>'Item Two', 'twoandhalf'=>'Item Two And Half', 'three'=>'Item Three', 'four'=>'Item Four', )); $iterator->setStartKey('two'); $iterator->setEndKey('three'); foreach($iterator as $key=>$value) { echo(''.$key.': '.$value."\r\n"); }