我有一個用 PHP 編寫的teampeak3 機器人，當我啟動機器人時出現此錯誤：PHP 警告：array_column() 期望參數 1 是數組，給定空值...在第 13 行，第 13 行是 $ clientonchannel，我不知道如何使它工作，感謝一些幫助。我是新手。PHP Code:    $config['function']['pokeonchannel'] = Array(        'enable' => true,        'info' => Array(            1 => Array(                'channel' => 20,                'pokegroup' => Array(103,110),                'message' => "[NICK] message to user",            )        ),        'interval' => Array('days' => 0, 'hours' => 0, 'minutes' => 0, 'seconds' => 30), //interval        'datazero' => '1970-01-01 00:00:00'    ); foreach($config['function']['pokeonchannel']['info'] as $pokeid)   {      $admincount = 0;      $admincount2 = 0;      $clientonchannel = array_keys(array_column($user['data'], 'cid'), $pokeid['channel']); **// This is line 13** if(isset($clientonchannel[0]))  {     foreach($pokeid['pokegroup'] as $pokegroup)     {        $groupclients = $tsAdmin -> serverGroupClientList($pokegroup, $names = true);             foreach($groupclients['data'] as $clientid)                 {                     $client = $tsAdmin -> clientFind($clientid['client_nickname']);                       if($client['data'])                                {                                    $admin = $tsAdmin-> clientInfo($client['data'][0]['clid']);                                    if(!in_array($admin['data']['cid'], $config['function']['helpchannel']['ignoredonchannel']))                                    {                                        $pokemessage = str_replace('[NICK]', $user['data'][$clientonchannel[0]]['client_nickname'], $pokeid['message']);                                        $tsAdmin -> clientPoke($client['data'][0]['clid'], $pokemessage);                                        $admincount++;}