3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php class App_Collection implements ArrayAccess, IteratorAggregate, Countable { public $data = array('x'=>null); public function count() { return count($this->data); } public function offsetExists($offset) { return isset($this->data[$offset])/* || array_key_exists($offset, $this->data)*/; } public function offsetGet($offset) { if ($this->offsetExists($offset)) { return $this->data[$offset]; } return false; } public function offsetSet($offset, $value) { if ($offset) { $this->data[$offset] = $value; } else { $this->data[] = $value; } } public function offsetUnset($offset) { unset($this->data[$offset]); } public function getIterator() { return new ArrayIterator($this->data); } } $array = new App_Collection(); var_dump(isset($array['x'])); var_dump(array_key_exists('x', $array));
based on gfitS
Output for 5.1.0 - 5.6.28, hhvm-3.12.0, 7.0.0 - 7.1.0
bool(false) bool(false)
Output for hhvm-3.10.0

Process exited with code 153.
Output for 5.0.5
Fatal error: Interface 'Countable' not found in /in/ZeGQo on line 2
Process exited with code 255.
Output for 5.0.0 - 5.0.4
Fatal error: Class 'Countable' not found in /in/ZeGQo on line 2
Process exited with code 255.
Output for 4.4.2 - 4.4.9
Parse error: syntax error, unexpected T_STRING, expecting '{' in /in/ZeGQo on line 2
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.4.1
Parse error: parse error, unexpected T_STRING, expecting '{' in /in/ZeGQo on line 2
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error, expecting `'{'' in /in/ZeGQo on line 2
Process exited with code 255.