2

I have the base class Manager and the derived class Worker, the inheritance seem to work properly - I've created a new object of the derived class using it's default constructor and i can output properly. but now I want to make an overloaded constructor for the derived class (Worker) and there seem to be a compilation error, I tired to look for an answer but I didn't found one. why the compiles says that Worker doesn't have id, name and salary fields? I've created a derived class by the book and created ctors for it.

Manager header:

#include <string>
#ifndef MANAGER_H
#define MANAGER_H

class Manager
{
public:
    Manager (); //ctor
    Manager (std::string, std::string, float, int); //overloaded ctor
    friend void display (Manager&); //friend function is declared
    ~Manager (); //dtor
protected:
    std::string id;
    std::string name;
    float salary;
private:
    int clearance;
};

Manager cpp:

#include <iostream>
#include "Manager.h"
#include "Worker.h"

Manager::Manager() //default ctor
{
id = "M000000";
name = "blank";
salary = 0;
clearance = 0;
}

Manager::Manager(std::string t_id, std::string t_name, float wage, int num): id (t_id), name      (t_name), salary(wage), clearance (num)
{
//overloaded ctor
}

Manager::~Manager()
{
 //dtor
}

Worker header:

#include <string>
#ifndef Worker_H
#define Worker_H

class Worker: public Manager
{
public:
    Worker();
    Worker (std::string, std::string, float, int);
    ~Worker();
     friend void display (Worker&); //friend function is declared
protected:
    int projects;
private:

};

#endif // Worker_H

Worker cpp:

#include <iostream>
#include "Manager.h"
#include "Worker.h"

Worker::Worker() //default ctor
{
id = "w000000";
name = " - ";
salary = 0;
projects = 0;

}
Worker::Worker(std::string t_id, std::string t_name, float wage, int num) : id (t_id), name (t_name), salary (wage), projects (num);
{
//ctor
}
Worker::~Worker()
{
//dtor
}
4

3 回答 3

2 
 Worker::Worker(std::string t_id, std::string t_name, float wage, int num) : id (t_id), name (t_name), salary (wage), projects (num)
{
//ctor
}

在这里你初始化基类中定义的成员id、name、salary和clearance。您需要将其传递给基类构造函数进行初始化。你不能直接初始化它们。
id,name并且clearance受到保护，因此您可以在派生类中访问它们，但不能使用初始化列表直接初始化它们。你可以initialize inside the constructor或make a call to base constructor in initialization list. 

Worker::Worker(std::string t_id, std::string t_name, float wage, int num):Manager(t_id,t_name,wage,0), projects (num)
{
//ctor
}
于 2014-07-09T20:07:39.520 回答
0

派生类看不到其基类的私有成员。您必须委托构造函数。

于 2014-07-09T20:05:28.280 回答
0

你的Worker构造函数应该是这样的：

Worker::Worker() : Manager("w000000", " - ", 0, 0) {}

Worker::Worker(std::string t_id, std::string t_name, float wage, int num) :
     Manager(t_id, t_name, wage, num)
{
}
于 2014-07-09T20:27:09.570 回答