c++ - 使用 C++ 继承的不可访问项

Question

我正在从事使用继承的 C++ 项目。我在下面的文件 administrator.h 中似乎在 visual studio 中有错误。它说第 17 行的 salariedemploye:salary 是不可访问的，我不确定为什么。

管理.cpp

#包含

namespace SavitchEmployees
{
    Administrator::Administrator( ):SalariedEmployee(), salary(0)
    {
        //deliberately empty
    }

    Administrator::Administrator(const string& theName, const string& theSsn, double theAnnualSalary)
      :SalariedEmployee(theName, theSsn),salary(theAnnualSalary)
    {
        //deliberately empty
    }

    void Administrator::inputAdminData()
    {
        cout << " Enter the details of the administrator " << getName() << endl;
        cout << " Enter the admin title" << endl;
        getline(cin, adminTitle);
        cout << " Enter the area of responsibility " << endl;
        getline(cin, workingArea);
        cout << " Enter the immediate supervisor's name " << endl;
        getline(cin, supervisorName);
    }

    void Administrator::outputAdminData()
    {
        cout << "Name: " << getName() << endl;
        cout << "Title: " << adminTitle << endl;
        cout << "Area of responsibility: " << workingArea << endl;
        cout << "Immediate supervisor: " << supervisorName << endl;
    }

    void Administrator::printCheck()
    {
        setNetPay(salary);
        cout << "\n___________________________________\n"
             << "Pay to the order of " << getName() << endl
             << "The sum of" << getNetPay() << "Dollars\n"
             << "______________________________________\n"
             << "Check Stub Not negotiable \n"
             << "Employee Number: " << getSsn() << endl
             << "Salaried Employee(Administrator). Regular Pay: "
             << salary << endl
             << "______________________________________\n";
    }
}

管理.h

#include <iostream>

#include "salariedemployee.h"
using std::endl;
using std::string;

namespace SavitchEmployees
{
    class Administrator : public SalariedEmployee
    {
        public:
            Administrator();
            Administrator(const string& theName, const string& theSsn, double salary);
            double getSalary() const;
            void inputAdminData();
            void outputAdminData();
            void printCheck();
        private:
            string adminTitle;//administrator's title
            string workingArea;//area of responsibility
            string supervisorName;//immediate supervisor
    };
}

#endif

受薪员工.cpp

namespace SavitchEmployees
{
    SalariedEmployee::SalariedEmployee():Employee(),salary(0)
    {
        //deliberately empty
    }
    SalariedEmployee::SalariedEmployee(const string& theName, const string& theNumber, double theWeeklyPay)
      :Employee(theName, theNumber), salary(theWeeklyPay)
    {
        //deliberately empty
    }
    double SalariedEmployee::getSalary() const
    {
        return salary;
    }
    void SalariedEmployee::setSalary(double newSalary)
    {
        salary = newSalary;
    }
    void SalariedEmployee::printCheck()
    {
        setNetPay(salary);
        cout << "\n___________________________________\n"
             << "Pay to the order of " << getName() << endl
             << "The sum of" << getNetPay() << "Dollars\n"
             << "______________________________________\n"
             << "Check Stub NOT NEGOTIABLE \n"
             << "Employee Number: " << getSsn() << endl
             << "Salaried Employee. Regular Pay: "
             << salary << endl
             << "______________________________________\n";
    }
}

薪水分配.h

#ifndef SALARIEDEMPLOYEE_H
#define SALARIEDEMPLOYEE_H

#include <string>
#include "employee.h"

namespace SavitchEmployees{
    class SalariedEmployee : public Employee{
    public:
        SalariedEmployee();
        SalariedEmployee(const string& theName, const string& theSsn, double theWeeklySalary);
        double getSalary() const;
        void setSalary(double newSalary);
        void printCheck();

    private:
        double salary;
    };
}
#endif

员工.cpp

namespace SavitchEmployees
{
    Employee::Employee():name("No name yet"),ssn("No number yet"),netPay(0){}
    Employee::Employee(const string& theName, const string& theSsn):name(theName),ssn(theSsn),netPay(0){}
    string Employee::getName() const
    {
        return name;
    }
    string Employee::getSsn() const
    {
        return ssn;
    }
    double Employee::getNetPay() const
    {
        return netPay;
    }
    void Employee::setName(const string& newName)
    {
        name = newName;
    }
    void Employee::setSsn(const string& newSsn)
    {
        ssn = newSsn;
    }
    void Employee::setNetPay(double newNetPay)
    {
        netPay = newNetPay;
    }
    void Employee::printCheck() const
    {
        cout << "\nERROR: pringCheck function called for an \n" 
             << "Undifferentiated employee. Aborting the program!\n"
             << "Check with the author of this program about thos bug. \n";
        exit(1);
    }
}

Answer 1

该变量在 Salariedemplyee.h 中声明为私有(private)。将其更改为 protected 以将其用于继承。

class SalariedEmployee : public Employee{
    public:
        SalariedEmployee();
        SalariedEmployee(const string& theName, const string& theSsn, double theWeeklySalary);
        double getSalary() const;
        void setSalary(double newSalary);
        void printCheck();

    private:
        double salary;
    };

第二个问题是成员变量的值只能在与该变量属于同一类的构造函数的初始化列表中设置。请改用赋值运算符。

Administrator::Administrator(const string& theName, const string& theSsn, double theAnnualSalary)
      :SalariedEmployee(theName, theSsn)
    {
        //deliberately empty
        salary = theAnnualSalary;
    }