3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array(0 => 200, '730404' => 89730 ,'730205' => 1000 ,'730100' => 1000 ,'730601' => 2184); $key='730404'; $keys = array_keys($array); print_r($keys); ?>
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, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.29 - 7.2.33, 7.3.12 - 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
Array ( [0] => 0 [1] => 730404 [2] => 730205 [3] => 730100 [4] => 730601 )
preferences:
253.49 ms | 406 KiB | 312 Q