Online PHP editor | refs for sRrvS

<?php $users = [ [ "name" => "Marcos", "roles" => [ "admin" => "2023-11-16T10:23:45Z", "reader" => "2023-11-16T10:24:23Z" ] ], [ "name" => "Roberto", "roles" => [ "admin" => "2023-11-16T10:23:45Z", ] ], [ "name" => "Jaime", "roles" => [ "admin" => "2023-11-16T10:23:45Z", "writer" => "2023-11-16T10:24:23Z" ] ], [ "name" => "Xabier", "roles" => [ "admin" => "2023-11-16T10:23:45Z", "writer" => "2023-11-16T10:24:23Z", "reader" => "2023-11-16T10:24:23Z" ] ] ]; foreach($users as &$u){ ksort($u['roles']); } usort($users, fn($a, $b) => strcmp( implode("|", array_keys($a['roles'])), implode("|", array_keys($b['roles'])) ) ); print_r($users);