Online PHP editor | refs for aWoPk

<?php class myIterator implements Iterator { public function __construct() { $this->position = 0; } public function rewind() { var_dump(__METHOD__); $this->position = 0; } public function current() { var_dump(__METHOD__); return $this->position; } public function key() { var_dump(__METHOD__); return $this->position; } public function next() { var_dump(__METHOD__); ++$this->position; } public function valid() { var_dump(__METHOD__); return true; } } $i = new LimitIterator(new myIterator, 0, 3); $i = new CachingIterator($i); $i->rewind(); echo "\n1st iteration\n"; echo $i->valid() ? "Valid\n" : "Not valid\n"; echo "Current key: ", $i->key() ?? 'NULL', "\n"; echo "Current value: ", $i->current() ?? 'NULL', "\n"; $i->next(); echo "\n2nd iteration\n"; echo $i->valid() ? "Valid\n" : "Not valid\n"; echo "Current key: ", $i->key() ?? 'NULL', "\n"; echo "Current value: ", $i->current() ?? 'NULL', "\n"; $i->next(); echo "\n3rd iteration\n"; echo $i->valid() ? "Valid\n" : "Not valid\n"; echo "Current key: ", $i->key() ?? 'NULL', "\n"; echo "Current value: ", $i->current() ?? 'NULL', "\n"; $i->next(); echo "\n4th iteration\n"; echo $i->valid() ? "Valid\n" : "Not valid\n"; echo "Current key: ", $i->key() ?? 'NULL', "\n"; echo "Current value: ", $i->current() ?? 'NULL', "\n"; $i->next(); echo "\n5th iteration\n"; echo $i->valid() ? "Valid\n" : "Not valid\n"; echo "Current key: ", $i->key() ?? 'NULL', "\n"; echo "Current value: ", $i->current() ?? 'NULL', "\n"; $i->next();