3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arrays = [ 252 => [ 0 => [ "id" => 2929850, "titulo" => " Film 1" ], 1 => [ "id" => 2929848, "titulo" => "Film 2" ] ], 251 => [ 0 => [ "id" => 2929796, "titulo" => "Film 3" ], 1 => [ "id" => 2929795, "titulo" => "Film 4" ] ] ]; $result = []; foreach ($arrays as $key => $array) { $result[$key] = array_keys($array); } print_r($result);
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.13
Array ( [252] => Array ( [0] => 0 [1] => 1 ) [251] => Array ( [0] => 0 [1] => 1 ) )
preferences:
141.55 ms | 408 KiB | 5 Q