how get ajax json response in ajax success function in laravel

Im using laravel

My ajax code in footer.blade

$(document).ready(function(){
        $('.drpbtn').change(function (event) {
            event.preventDefault();
            $id=this.id;
            $size=$('option:selected', this).val();
            $.ajax({
                    url:"", 
                    dataType:"json",
                    type:"post",
                    data:{
                    id:$id,
                    size:$size,
                    "_token": "",
                    },
                    success: function(result){ 
                        alert(result);
                        console.log(result);
                    }
                });
        });
    });

My Route is Route::match(['get','post'],'/size_ajax','ajaxcontrol@size_ajax');

Im fetching row from my database using query builder with two condition, and my

My ajaxcontroller.blade

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Session;
use App\Http\Requests;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\Response;
use App\product;
use App\prodattr;
use DB;

class ajaxcontrol extends Controller
{
 public function size_ajax(Request $request){
        $id = $request->id;
        $size = $request->size;     
        $p_sku_sel = Prodattr::select('p_sku')->where([['p_id','=',$id],['size','=',$size]])->get();
        $response = ['p_sku_sel' => $p_sku_sel];
        return response()->json($response,200);
    }
}

When I console the result in footer.blade it shows

    {p_sku_sel: Array(1)}
p_sku_sel: [{…}]
__proto__: Object

But when I alert the result in footer.blade it shows

[Object] [Object]

Can anyone help me how to get the p_sku: value in ajax success function in footer.blade

via Chebli Mohamed