3v4l.org

run code in 500+ PHP versions simultaneously
<?php $users = [ 'abc' => 'Display name of ABC', '123' => 'Display name of 123', ]; foreach ($users as $userId => $displayName) { var_dump($userId); var_dump(is_string($userId)); }
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11
string(3) "abc" bool(true) int(123) bool(false)
preferences:
31.76 ms | 1136 KiB | 7 Q