3v4l.org

run code in 300+ PHP versions simultaneously
<?php $data = array('key' => null); var_dump(isset($data['key'])); var_dump(array_key_exists('key', $data)); var_dump(isset($data['key']) && $data['key']);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.29, 8.2.0 - 8.2.23, 8.3.0 - 8.3.11
bool(false) bool(true) bool(false)
preferences:
80.04 ms | 409 KiB | 5 Q