C++快速入門---多繼承(20)
阿新 • • 發佈:2018-11-18
C++快速入門---多繼承(20)
只要你遇到的問題無法只用一個“是一個”關係來描述的時候,就是多繼承出場的時候。
例子:
有一部分學生還教課掙錢(助教),這樣就存在了即是老師又是學生的複雜關係,也就是同時存在著兩個“是一個”關係。
我們需要寫一個TeachingStudent類讓它同時繼承Teacher類和Student類,換句話說,就是需要使用多繼承。
基本語法:
class TeachingStudent : public Student, public Teacher
{...}
程式碼如下:
#include <iostream> #include <string> class Person { public: Person(std::string theName); void introduce(); protected: std::string name; }; class Teacher : public Person { public: Teacher(std::string theName, std::string theClass); void teach(); void introduce(); protected: std::string classes; }; class Student : public Person { public: Student(std::string theName, std::string theClass); void attendClass(); void introduce(); protected: std::string classes; }; //助教 class TeachingStudent : public Student, public Teacher { public: TeachingStudent(std::string theName, std::string classTeaching, std::string classAttending); void introduce(); }; Person::Person(std::string theName) { name = theName; } void Person::introduce() { std::cout << "大家好,我是" << name << ".\n\n"; } Teacher::Teacher(std::string theName, std::string theClass) : Person(theName) { classes = theClass; } void Teacher::teach() { std::cout << name << "教" << classes << ".\n\n"; } void Teacher::introduce() { std::cout << "大家好,我是" << name << ",我教" << classes << ".\n\n"; } Student::Student(std::string theName, std::string theClass) : Person(theName) { classes = theClass; } void Student::attendClass() { std::cout << name << "加入" << classes << "學習.\n\n"; } void Student::introduce() { std::cout << "大家好,我是" << name << ",我在" << classes << "學習.\n\n"; } TeachingStudent::TeachingStudent(std::string theName, std::string classTeaching, std::string classAttending) : Teacher(theName, classTeaching), Student(theName, classAttending) { } void TeachingStudent::introduce() { std::cout << "大家好,我是" << Student::name << ".我教" << Teacher::classes << ","; } int main() { Teacher teacher("小甲魚", "C++入門班"); Student student("迷途羔羊", "C++入門班"); TeachingStudent teachingStudent("丁丁", "C++入門班", "C++進階版"); teacher.introduce(); teacher.teach(); student.introduce(); student.attendClass(); teachingStudent.introduce(); teachingStudent.teach(); teachingStudent.attendClass(); return 0; }