C++ 继承和派生的应用 1.定义一个类 Book, 用来描述新书, 具有以下功能:(1) 查看当前价格. (2)查看当前的书号 2.定义一个类 SellBook, 用来表示促销的书籍, 要求继承自 Book 类 具有以下功能: 1. 查看当前折扣 2. 设置当前折扣 3. 查看当前的促销价格

#pragma once #include <string>
using namespace std; class Book { public: Book(const string& bookname, const string& isbn, double price); double getPrice(); string getISBN(); string getBookname(); protected: double price; string ISBN; string bookname; };

#include "Book.h" Book::Book(const string& bookname, const string& isbn, double price) { this->bookname = bookname; this->ISBN = isbn; this->price = price; } double Book::getPrice() { return price; } string Book::getISBN() { return ISBN; } string Book::getBookname() { return bookname; }

#pragma once #include "Book.h" #include <string>
using namespace std; class Sellbook : public Book { public: Sellbook(string bookname, string isbn, double price, double discount = 10.0); void setDiscount(double discount); double getDiscount(); double getPrice(); private: double discount; };

#include "Sellbook.h" Sellbook::Sellbook(string bookname, string isbn, double price, double discount ) :Book(bookname,isbn,price) { this->discount = discount; } void Sellbook::setDiscount(double discount) { this->discount = discount; } double Sellbook::getDiscount() { return discount; } double Sellbook::getPrice() { return price * discount * 0.1; }

#include <iostream> #include <string> #include "Book.h" #include "Sellbook.h"
using namespace std; int main() { Book b1("C程序设计","02222",50); Sellbook b2("C++程序设计","300012",24); cout << b1.getBookname() << "的原价是：" << b1.getPrice() << ",书号是：" << b1.getISBN() << endl; cout << b2.getBookname() << "的原价是：" << b2.getPrice() << ",书号是：" << b2.getISBN() << endl; b2.setDiscount(5.0); cout << b2.getBookname() << "的折扣是：" << b2.getDiscount() << endl; cout << b2.getBookname() << "打折后的价格是：" << b2.getPrice() << ",书号是：" << b2.getISBN() << endl; system("pause"); return 0; }