3v4l.org

run code in 300+ PHP versions simultaneously
<? $yourArray = array('first_key'=> 'First', 2, 3, 4, 5); $first_key = current(array_flip($yourArray)); echo $first_key;
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.30, 8.0.0 - 8.0.20, 8.1.0 - 8.1.7
<? $yourArray = array('first_key'=> 'First', 2, 3, 4, 5); $first_key = current(array_flip($yourArray)); echo $first_key;

preferences:
96.49 ms | 410 KiB | 5 Q