数组赋值的有关问题

数组赋值的问题

public function setParm($parameter, $value) {
		$this->parameter[$parameter] = $value;
		return $this;
	}

function geturl($type){
     $this->setproductparm($type);
     return $this->getData();
     }  
   
private function setproductparm($urltype){
     $this->parameter=array();
     $this->type="";
     $this->setParm("Marketplace",self::marketplaceId);
     $this->version="2009-01-01";
     switch ($urltype){
        case "RequestReport":    
            $this->setParm("Action","RequestReport");
            $this->setParm("ReportType","_GET_MERCHANT_LISTINGS_DATA_");
        break;
        case "GetReportList":  
            $this->setParm("Action","GetReportList");   
            $this->setParm("ReportRequestIdList.Id.1",$this->ReportRequestId);
        break;
        case "GetReport":  
            $this->setParm("Action","GetReport");   
            $this->setParm("ReportId",$this->ReportId);  
        break;   
          
              
        }
        
     }

$url1=$aa->geturl("RequestReport");
$url2=$aa->geturl("GetReportList");
$url3=$aa->geturl("GetReport");

我明明每次执行前都清除了数组
$this->parameter=array();
但输出时，每次数组都包含了上次所赋的值。
每次结果：
$url1：ReportType=_GET_MERCHANT_LISTINGS_DATA_
$url2：ReportType=_GET_MERCHANT_LISTINGS_DATA_&ReportRequestIdList.Id.1=123456
$url3：ReportType=_GET_MERCHANT_LISTINGS_DATA_&ReportRequestIdList.Id.1=123456&ReportId=123456

请问是哪里的问题啊？？？
------解决思路----------------------
你没有给出 getData 的定义，不好说
------解决思路----------------------

//看看是不是下面的方法哪里处理了
getData();