3v4l.org

run code in 300+ PHP versions simultaneously
<?php if(!function_exists("array_key_first")){ function array_key_first($array){ reset($array); return key($array); } } $array = [55 => "lol", 44 => 287]; while (current($array)) { next($array); } var_dump(array_key_first($array)); var_dump(current($array));
Output for 5.6.38, 7.0.33, 7.1.25, 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 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
int(55) bool(false)
preferences:
100.24 ms | 1384 KiB | 4 Q