C ++对象作为类成员

Question

making object from Address and trying to refer to it is not working

   Student::Student(string studentInfo_c){ // student constructor
       stringstream ss(studentInfo_c);

       getline(ss, lastName, ',');
       getline(ss, firstName, ',');
       getline(ss, address1, ',');
       getline(ss, address2, ',');
       getline(ss, city, ',');
       getline(ss, state, ',');
       getline(ss, zipCode, ',');


       Address sAddrs(address1, address2, city, state, zipCode);



  }

      ostream& operator<<(ostream& os, const Student& s){  os << s.lastName << ", " << s.firstName << " " << s.aAddrs;
      return os; // first place that sAddrs oject is referenced
  }

class prototypes:

class Student {

  private:

    string line;

    string lastName;
    string firstName;
    string address1;
    string address2;
    string city;
    string state;
    string zipCode;
public:
    //Student() : Address aAddrs   this didnt work...
    Student(string studentInfo_c);
    string get_firstName();
    string get_lastName();
    void set_address(string address1_f, string address2_f, string city_f, string state_f, string zipCode_f);

    friend ostream& operator<<(ostream& os, const Student& s);

    ~Student();

}

error: In function 'std::ostream& operator<<(std::ostream&, const Student&)':| C:\\Users\\Chris\\Documents\\Summer 2017 Semesters\\HeapOStudents\\student.cpp|67|error: 'const class Student' has no member named 'aAddrs'|

C:\\Users\\Chris\\Documents\\Summer 2017 Semesters\\df\\student.cpp|73|error: 'aAddrs' was not declared in this scope|

||=== Build failed: 6 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|

ps I know this is similar to other questions but none of them have seemed to work for me, they are slightly more advanced.

thanks,

Answer 1

According to recommendations in comments, I assembled an MCVE to show how it could be done:

#include <iostream>
#include <sstream>
#include <string>

using namespace std;

class Address {
  private:
    string address1;
    string address2;
    string city;
    string state;
    string zipCode;
  public:
    // default constructor (leaving contents empty)
    Address() { }
    // constructor.
    Address(
      const string &address1, const string &address2,
      const string &city, const string &state,
      const string &zipCode):
      address1(address1), address2(address2),
      city(city), state(state), zipCode(zipCode)
    { }

    friend ostream& operator<<(ostream& os, const Address &a);
};

ostream& operator<<(ostream& os, const Address &a)
{
  return os
    << "  Address 1: " << a.address1 << endl
    << "  Address 2: " << a.address2 << endl
    << "  City     : " << a.city << endl
    << "  State    : " << a.state << endl
    << "  Zip Code : " << a.zipCode << endl;
}

class Student {
  private:
    string lastName;
    string firstName;
    Address sAddrs;

  public:
    // constructor.
    Student(const string &studentInfo_c);

    friend ostream& operator<<(ostream& os, const Student &s);
};

Student::Student(const string &studentInfo_c)
  // all members are default constructed (leaving them empty)
{
  stringstream ss(studentInfo_c);
  getline(ss, lastName, ',');
  getline(ss, firstName, ',');
  string address1, address2, city, state, zipCode;
  getline(ss, address1, ',');
  getline(ss, address2, ',');
  getline(ss, city, ',');
  getline(ss, state, ',');
  getline(ss, zipCode, ',');
  sAddrs = Address(address1, address2, city, state, zipCode);
}

ostream& operator<<(ostream &os, const Student &s)
{
  return os
    << "Student " << s.lastName << ", " << s.firstName << endl
    << "Address: " << endl
    << s.sAddrs << endl;
}

int main()
{
  string sample("Doe,John,1 Anyway,,Anytown,Anystate,12345,");
  Student s(sample);
  cout << s;
  return 0;
}

Tested with g++:

$ g++ -std=c++11 -o test test.cc

$ ./test
Student Doe, John
Address: 
  Address 1: 1 Anyway
  Address 2: 
  City     : Anytown
  State    : Anystate
  Zip Code : 12345


$

Notes:

1. Address provides two constructors: a default constructor and a second one for initialization.

2. Student::Student constructs all members with default constructors. (Therefore, Address has to provide one.)

3. In the body of Student::Student , a temporary instance of Address is created and assigned to Student::sAddrs . This works because the assignment operator ( Address& Address::operator=(const Address&) ) is generated by the compiler. (This is not the most efficient code but the one with least source code effort.)