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

Book.h:

#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;
};

Book.cpp:

#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;
}

Sellbook.h:

#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;
};

Sellbook.cpp:

#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;
}

main.cpp:

#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;
}