c++ - 我可以有一个子类的子类吗？如何继承父代和其他子类的特征而没有错误？

Question

因此，下面是一些我正在练习继承的代码，创建了一个Employee类，并在其下创建了一些子类。它们各自都按预期运行，但是当我有Lawyer和harvardLawyer时，我希望harvardLawyer拥有与Lawyer不同的构造函数(不同的构造函数变量，工时，薪水等)，但保留所有其他内容(在这种情况下，只是sue()方法)相同。

现在，我不想复制该方法，而是要继承它。我已经尝试了多种方法。

经过几次编辑...

error: no matching constructor for initialization of 'lawyer'

我该如何解决？

#include <iostream>
#include <stdio.h>
using namespace std;

class employee {
private:
    int baseHours = 40;
    double baseSalary = 40000.0;
    int baseVacationDays = 10;
    string baseVacationForm = "yellow";

public:
    employee(int hours = 40, double salary = 40000.0, int days = 10,
             string form = "yellow") {
        baseHours = hours;
        baseSalary = salary;
        baseVacationDays = days;
        baseVacationForm = form;
    }

    int getHours() { return baseHours; }
};

class lawyer : public employee {
public:
    lawyer() : employee(80, 30000.0, 15, "pink") {}

    string sue() { return "I'll see you in court!"; }
};

class harvardLawyer : public lawyer {
public:
    harvardLawyer() : lawyer(80, 36000.0, 18, "pink pink pink pink") {}
};

int main() {
    lawyer c;
    harvardLawyer d;
    cout << c.getHours() << "\n" << d.getHours() << "\n"; //<<d.sue();

    return 0;
}

Answer 1

在harvardLawyer构造函数中，您尝试调用lawyer(int, double, int, string)构造函数。但是，您的lawyer类仅具有lawyer()构造函数。您正在尝试调用一个不存在的函数。

要解决您的紧迫问题，您应该修改lawyer构造函数以采用要传递给它的所有参数。您仍然可以指定默认参数-这允许您使用零，一，二，三或四个参数(按显示的顺序)调用构造函数。你的选择。

class lawyer : public employee {
public:
    lawyer(int hours = 80,
           double salary = 30000.0,
           int days = 15,
           string tag = "pink") : employee(hours, salary, days, tag) {}

    string sue() { return "I'll see you in court!"; }
};

class harvardLawyer : public lawyer {
public:
    harvardLawyer() : lawyer(80, 36000.0, 18, "pink pink pink pink") {}
};

但是，尚不清楚为什么根本需要 harvardLawyer类。如果需要 harvardLawyer，只需创建一个 lawyer并传递适当的参数即可。假设 harvardLaywer不再是一个类:

int main(int argc, char** argv)
{
    lawyer regular_lawyer = lawyer();
    lawyer harvard_lawyer = lawyer(80, 36000.0, 18, "pink pink pink pink");
    std::cout << harvard_lawyer.sue() << "\n";
}