Online PHP editor | output for AQ2WT

<?php namespace Test; class SegmentCollection { private $segmentArray = []; public function __construct(array $segmentArray) { $this->segmentArray = $segmentArray; } public function popSegment() { return array_pop($this->segmentArray); } public function shiftSegment() { return array_shift($this->segmentArray); } } interface SegmentReader { public function getNextSegment(); } abstract class SegmentReaderBase implements SegmentReader { protected $segmentCollection; public function __construct(SegmentCollection $segmentCollection) { $this->segmentCollection = $segmentCollection; } } class PopSegmentReader extends SegmentReaderBase { public function getNextSegment() { return $this->segmentCollection->popSegment(); } } class ShiftSegmentReader extends SegmentReaderBase { public function getNextSegment() { return $this->segmentCollection->shiftSegment(); } } function acceptSegmentReader(SegmentReader $segmentReader) { var_dump($segmentReader->getNextSegment()); var_dump($segmentReader->getNextSegment()); } $segmentCollection = new SegmentCollection(['foo', 'bar', 'qux', 'zip']); acceptSegmentReader(new PopSegmentReader($segmentCollection)); acceptSegmentReader(new ShiftSegmentReader($segmentCollection));