Ajax傳一個數組數據

HTML

<form   method="post" action="">
<input  type="checkbox" name="checkbox" value="1">1
<input  type="checkbox" name="checkbox" value="2">2
<input  type="checkbox" name="checkbox" value="3">3
<input  type="checkbox" name="checkbox" value="4">4
<input  type="button" value="添加" onClick="addRegion()">
</form> 

button按鈕調用addRegion方法

function addRegion(){
      var str="";
      $("input[name='checkbox']:checkbox").each(function(){
           if($(this).is(":checked")){
               str += $(this).val()+","
           }
       })
       str.split(",");
       if(str==""){
           str = '您還沒有選擇';
           alert(str);
           return false;
       } else {
       }
       $.ajax(
               {
                   type:"POST",
                   data:{regional:str},
                   url:'/Item/addRegionalModels',
                   dataType:"json",
                   success:function(msg)
                   {
                       if(msg.ret == 1){
                           modalAlert('提示','添加成功');
                       }else{
                           modalAlert('提示','添加失敗');
                       }

                   }
               }
       )
}

控制器/Item/addRegionalModels

public  function  addRegionalModels(){
        $data['regional']  =$_POST['regional'];
        $newstrs = substr($data['regional'],0,strlen($data['regional'])-1);
        $arr = explode(",",$newstrs);
        foreach($arr as $u){
            $strarr = explode(",",$u);
            foreach($strarr as $newstr){
                $sql = "INSERT into test(brand) VALUES('".$newstr."')";
                $list = $Model->query($sql);
            }
         }
}