3v4l.org

run code in 300+ PHP versions simultaneously
<?php $search_array = array('first' => null, 'second' => 4); // returns false echo "1: ".(isset($search_array['first'])?'TRUE':'FALSE').PHP_EOL; // returns true echo '2: '.(array_key_exists('first', $search_array)?'TRUE':'FALSE').PHP_EOL; ?>
Output for 4.3.10 - 4.3.11, 4.4.0 - 4.4.9, 5.0.2 - 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
1: FALSE 2: TRUE
Output for 4.3.0 - 4.3.9, 5.0.0 - 5.0.1
Notice: Use of undefined constant PHP_EOL - assumed 'PHP_EOL' in /in/Qs8eb on line 5 1: FALSEPHP_EOL Notice: Use of undefined constant PHP_EOL - assumed 'PHP_EOL' in /in/Qs8eb on line 8 2: TRUEPHP_EOL
preferences:
305.29 ms | 402 KiB | 460 Q