struct student{
       uint grade;
       string name;
       mapping(uint=>string) map;
   }
student memory s = student(100,"jonson"); //初始化不用管mapping
// s.map[2] = "alice";錯誤，mapping映射只能夠存儲在storage空間中

contract structdeep{


    struct student{
        uint grade;
        string name;
        mapping(uint=>string) map;
    }

    student stu;


    function init() public view returns(string){
        student memory s = student(100,"jonson");

        //將memory中 結構體s的值賦值給狀態變量中的stu。
        stu =  s;
        //操作mapping映射
       stu.map[2] = "alice";

      //引用
      student storage guy =  stu;
      guy.map[2] = "bob";


      return stu.map[2];

    }

struct student{
    uint grade;
    string name;
}

function structParam(student s) internal{
    student memory guy =  s;
}

struct student{
    uint grade;
    string name;
}

function structParam(student s) internal{
    student  guy =  s;
}

struct student{
    uint grade;
    string name;
}

function structParam(student s) internal{
    student storage guy =  s;
}

function structParam2(student storage s) internal{
    student storage guy =  s;
    guy.grade = 1000;
}

function call() public returns(uint){

    structParam2(stu);

    return stu.grade;