Php Magento代码需要精确性

我目前正在检查Magento扩展，我对一段代码有点怀疑。我想请你解释一下。我完全理解，但不是这一点：

$customerID == " "

Magento是否有这样的客户id（空间？）？ 非常感谢您的回复！ 这里是整个函数

public function isAvailable(Varien_Event_Observer $observer)
{

    $event           = $observer->getEvent();
    $method          = $event->getMethodInstance(); //$method return the payment method
    $result          = $event->getResult();         //$result return true if method is active
    $quote           = $event->getQuote();          //$quote return var from cart
    if($method->getCode() == 'custompayment' ){
        //$customerGroup        = $quote->getCustomerGroupId();
        // $customerGroup="";
        // $customerID="";
         $login = Mage::getSingleton( 'customer/session' )->isLoggedIn(); //Check if User is Logged In
    if($login)
    {
        $customerGroup = Mage::getSingleton('customer/session')->getCustomerGroupId(); //Get Customers Group ID
        $customerID = Mage::getSingleton('customer/session')->getCustomerId(); //Get Customers ID

    }
        $selectedCustomerGroups =   Mage::getStoreConfig('payment/custompayment/specificcustomers');
        $selectedCustomerGroupsArray = explode(",", $selectedCustomerGroups);
            if($selectedCustomerGroups != "" || $customerID == " "){
                if(!in_array($customerGroup, $selectedCustomerGroupsArray)) {
                            $result->isAvailable = false;
                    } 

            }
            else{
               if($result->isAvailable==1){
                    $result->isAvailable = true;
                }
            }

    }

---

由adrien54和JokiRuiz回答。

据我所知，没有，但您可以查看表“customer_entity”并检查您是否有空间id。我猜他们会想测试$customerID是否为空，并错误地放置一个空间好的。我认为两者都是真的。“customer_实体”不显示任何空格。谢谢你们两位；）