3v4l.org

run code in 300+ PHP versions simultaneously
<?php $error = array( 'qwerty1' => 1, 'qwerty3' => 3 ); $error = array_slice($error, 0, 1, true) + array('qwerty2' => 2) + array_slice($error, 1, NULL, true); var_dump($error);
Output for 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 - 8.3.27, 8.4.1 - 8.4.14
array(3) { ["qwerty1"]=> int(1) ["qwerty2"]=> int(2) ["qwerty3"]=> int(3) }
preferences:
153.35 ms | 408 KiB | 5 Q