我做了一個(gè)小游戲，客戶端向服務(wù)器發(fā)送 '{"type":"update","boatId":"20001","y":"10"}' json數(shù)據(jù)，服務(wù)端把y 值存到數(shù)組$POSITION中，如果有新的用戶進(jìn)入，會(huì)先發(fā)送 '{"type":"init"}'，服務(wù)端判斷type為init則吧數(shù)組中的數(shù)據(jù)發(fā)送到客戶端。那么問(wèn)題是：每次有新的客戶端打開(kāi)，或者刷新頁(yè)面，客戶端收到的數(shù)組數(shù)據(jù)總是會(huì)變。打印$POSITION發(fā)現(xiàn)值每次都不一定固定。怎么回事兒？
下面是我的代碼

$POSITION = array('boat1' =>0,'boat2' =>0,'boat3' =>0);     
class Event
{
   public static function onMessage($client_id, $message)
   {
    global $POSITION;

    // $message = '{"type":"update","boatId":"20001","y":"1"}'
        $message_data = json_decode($message, true);

        if(!$message_data)
        {
            return ;
        }   

        switch($message_data)
        {
            case 'init':
                Gateway::sendToAll(json_encode(array(
                    'type' => 'init',
                    'boat1' => $POSITION,
                    'boat2' => $POSITION,
                    'boat3' => $POSITION,
                )));
            return;
            //更新數(shù)據(jù)
            case 'update':
                $boatId = $message_data;
                $y = 10;
                if($boatId != null){
                    switch($boatId){
                        case '20001' : $POSITION += $y; break;
                        case '20002' : $POSITION += $y; break;
                        case '20003' : $POSITION += $y; break;
                    }
                }
                Gateway::sendToAll($message);
                return;
        }
   }
}