Update Multiple Row using Linq

some time it requires to update multiple record using linq , for selecting single value you have to use Dirstdefault() , but for selecting multiple value you have to use list like below

var userId=Convert.ToInt32(outuserId.Value);
var res = context.tblCarts.Where(i => i.Cookies_Id == Cartcokie.Value).ToList();
res.ForEach(a => a.User_Id = userId);
context.SaveChanges();