c++ - 如何继承方法然后向它们添加一些东西？

Question

class uni_person {
    public:
    string f_name;   // 1
    string s_name;   // 2
    int age;         // 3
    string institute;// 5
    string uni;      // 6 
    string p_number; // 7

    void addSmth() {
        int x;
        cout << "What do you want to add about the student ?\n1: first name\n2: second name\n3: age\n4: course\n5: institute\n6: university\n7: phone number\n8: group\n";
        cin >> x;
        switch (x) {
            case 1: cin >> f_name; break;
            case 2: cin >> s_name; break;
            case 3: cin >> age; break;
            case 5: cin >> institute; break;
            case 6: cin >> uni; break;
            case 7: cin >> p_number; break;
            default: cout << "Error" << endl; break;
        }
    }
};

class Student: public uni_person {
    public:
    int course;
    int group;

    void addSmth() {
        int x;
        cout << "What do you want to add about the student ?\n1: first name\n2: second name\n3: age\n4: course\n5: institute\n6: university\n7: phone number\n8: group\n";
        cin >> x;
        switch (x) {
            case 4: cin >> course; break;
            case 8: cin >> group; break;
        }
    }
};

所以我有一个问题，我目前正在学习 C++ 中的 OOP，我遇到了这个问题......如何让类继承其他类的方法并向其添加新的东西而不重写它？它有什么特殊功能吗？我重写了 addSmth() 并想向 addSmth() 添加更多行为。

Answer 1

首先，您应该将用户交互与实际逻辑分开。如果你有，你可以从 Derived 函数显式调用 Base 函数:

您还应该将基函数标记为 virtual 并将派生函数标记为 override。

virtual void uni_person::promptAddSmth()
{
    cout << "What do you want to add about the student ?\n1: first name\n2: second name\n3: age\n4: course\n5: institute\n6: university\n7: phone number\n8: group\n";
    int x;
    cin >> x;
    addSmth(x);
}

virtual void uni_person::addSmth(int x)
{
    switch (x) {
    case 1: cin >> f_name; break;
    case 2: cin >> s_name; break;
    case 3: cin >> age; break;
    case 5: cin >> institute; break;
    case 6: cin >> uni; break;
    case 7: cin >> p_number; break;
    default: cout << "Error" << endl; break;
    }
}

void Student::promptAddSmth() override
{
    cout << "What do you want to add about the student ?\n1: first name\n2: second name\n3: age\n4: course\n5: institute\n6: university\n7: phone number\n8: group\n";
    int x;
    cin >> x;
    addSmth(x);
}

void Student::addSmth(int x) override
{
    switch(x) {
    case 4: cin >> course; break;
    case 8: cin >> group; break;
    default: uni_person::addSmth(x); break;
    }
}