C++對象爲類成員

Question

從地址製作對象，並試圖指它不工作

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 
    } 

類原型：

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(); 

}

錯誤： 在函數「STD :: ostream &運營商< <（std :: ostream &，const學生&）'：| 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學期\ df \ student.cpp | 73 |錯誤：'aAddrs'未在此範圍內聲明|

|| ===構建失敗：6個錯誤，0個警告（0分鐘，0秒）===

p.s. 我知道這與其他問題類似，但他們都沒有爲我工作，他們稍微更先進。

感謝，

Answer 1

根據意見建議，我組建了一個MCVE顯示它如何能做到：

#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; 
} 

測試與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 


$ 

注：

1. Address提供了兩個構造函數：默認構造函數和第二個用於初始化的構造函數。

2. Student::Student構造具有默認構造函數的所有成員。 （因此，具有Address以提供一個。）

3. 在Student::Student體內，被創建並分配給Student::sAddrs的Address一個臨時的實例。這是有效的，因爲賦值運算符（Address& Address::operator=(const Address&)）由編譯器生成。 （這不是最有效的代碼，而是最少使用源代碼的代碼。）