3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array_1 = array("1a" =>"dogs","2a" => "cats","3a" => "birds","4a" => "people"); $array_2 = array("4a" => "walking","2a" => "cats"); foreach ($array_1 as $key_1 => $value_1) { if (array_key_exists($key_1, $array_2)) { $array_1[$key_1] = $array_2[$key_1]; } } print_r($array_1);
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, 5.5.0 - 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
Array ( [1a] => dogs [2a] => cats [3a] => birds [4a] => walking )
preferences:
268.45 ms | 406 KiB | 460 Q