第十三章 类继承

第十三章 类继承

第一题：以已有类，派生出一个新类，并用指定程序进行测试。

//fiel1 onehead.h#ifndef ONEHEAD_H_#define ONEHEAD_H_#include<string>#include<iostream>using std::cout;using std::endl;class Cd{//private:protected:    char performers[50];    char label[20];    int selections;    double playtime;public:    Cd(){};    Cd(char *s1, char *s2, int n, double x);    Cd(const Cd &d);    virtual ~Cd(){};    virtual void Report()const;    //virtual Cd & operator=(const Cd & d);};#endif

//file2 oneheadplus.h#ifndef ONEHEADPLUS_H_#define ONEHEADPLUS_H_#include"onehead.h"class Classic:public Cd{public:    Classic(){};    Classic(char *s3, char *s1, char *s2, int n, double x);    ~Classic(){};    void Report()const;    virtual Classic & operator=(const Classic & d);private:    char abstract[60];};#endif

//file3 onehead.cpp#include"onehead.h"Cd::Cd(char *s1, char *s2, int n, double x){    strncpy_s(performers, s1, 49);    strncpy_s(label, s2,19 );    selections = n;    playtime = x;}Cd::Cd(const Cd &d){    strcpy_s(performers, d.performers);    strcpy_s(label, d.label);    selections = d.selections;    playtime = d.playtime;}void Cd::Report()const{    cout << "----CD Methord----" << endl;    cout << "Performers: " << performers << endl;    cout << "Label     : " << label << endl;    cout << "Slections : " << selections << endl;    cout << "Play time : " << playtime << endl;}

//file4 oneheadplus.cpp#include"oneheadplus.h"Classic::Classic(char *s3, char *s1, char *s2, int n, double x) :Cd(s1, s2, n, x){    strncpy_s(abstract, s3, 59);}void Classic::Report()const{    cout << "----Classic Methord----" << endl;    cout << "Abstract  : " <<abstract << endl;    cout << "Performers: " << performers << endl;    cout << "Label     : " << label << endl;    cout << "Slections : " << selections << endl;    cout << "Play time : " << playtime << endl;}Classic & Classic::operator=(const Classic & d){    if (this == & d)        return *this;    strcpy_s(abstract, d.abstract);    strcpy_s(performers, d.performers);    strcpy_s(label, d.label);    selections = d.selections;    playtime = d.playtime;    return *this;}

//file5 one.cpp#include"oneheadplus.h"void Bravo(const Cd &disk);int main(){    Cd c1("Beatles", "Capitol", 14, 35.5);    Classic c2 = Classic("Piano Sonata in B flat ,Fantasia in C", "Alfred Brendel"        , "Philips", 2, 57.17);    Cd *pcd = &c1;    cout << "Using object directly: \n\n";    c1.Report();    c2.Report();    cout << "\n\nUsing type cd* pointer to object : \n\n";    pcd->Report();    pcd = &c2;    pcd->Report();    cout << "\n\nCalling a function with a Cd reference argument: \n\n";    Bravo(c1);    Bravo(c2);    cout << "\n\nTesting assigment: \n\n";    Classic copy;    copy = c2;    copy.Report();    system("pause");    return 0;}void Bravo(const Cd&disk){    disk.Report();}

第二题：重写上一题，利用动态内存分配。
与第一题代码基本相同只有少部分修改。

//file1 onehead.h#ifndef ONEHEAD_H_#define ONEHEAD_H_#include<string>#include<iostream>using std::cout;using std::endl;class Cd{//private:protected:    //char performers[50];    //char label[20];    char *performers;    char *label;    int selections;    double playtime;public:    Cd(){};    Cd(char *s1, char *s2, int n, double x);    Cd(const Cd &d);    virtual ~Cd(){};    virtual void Report()const;};#endif

//file2 oneheadplus.cpp#ifndef ONEHEADPLUS_H_#define ONEHEADPLUS_H_#include"onehead.h"class Classic:public Cd{public:    Classic(){};    Classic(char *s3, char *s1, char *s2, int n, double x);    ~Classic(){};    void Report()const;    virtual Classic & operator=(const Classic & d);private:    //char abstract[60];    char *abstract ;};#endif

//file3 onehead.cpp#include"onehead.h"Cd::Cd(char *s1, char *s2, int n, double x){    performers=s1;    label=s2;    //strncpy_s(performers, s1, 49);    //strncpy_s(label, s2,19 );    selections = n;    playtime = x;}Cd::Cd(const Cd &d){    performers = d.performers;    label = d.label;    //strcpy_s(performers, d.performers);    //strcpy_s(label, d.label);    selections = d.selections;    playtime = d.playtime;}void Cd::Report()const{    cout << "----CD Methord----" << endl;    cout << "Performers: " << performers << endl;    cout << "Label     : " << label << endl;    cout << "Slections : " << selections << endl;    cout << "Play time : " << playtime << endl;}

//file4 oneheadplus.cpp#include"oneheadplus.h"Classic::Classic(char *s3, char *s1, char *s2, int n, double x) :Cd(s1, s2, n, x){    abstract=s3;    //strncpy_s(abstract, s3, 59);}void Classic::Report()const{    cout << "----Classic Methord----" << endl;    cout << "Abstract  : " <<abstract << endl;    cout << "Performers: " << performers << endl;    cout << "Label     : " << label << endl;    cout << "Slections : " << selections << endl;    cout << "Play time : " << playtime << endl;}Classic & Classic::operator=(const Classic & d){    if (this == & d)        return *this;    abstract = d.abstract;    performers = d.performers;    label = d.label;    //strcpy_s(abstract, d.abstract);    //strcpy_s(performers, d.performers);    //strcpy_s(label, d.label);    selections = d.selections;    playtime = d.playtime;    return *this;}

//file5 one.cpp#include"oneheadplus.h"void Bravo(const Cd &disk);int main(){    Cd c1("Beatles", "Capitol", 14, 35.5);    Classic c2 = Classic("Piano Sonata in B flat ,Fantasia in C", "Alfred Brendel"        , "Philips", 2, 57.17);    Cd *pcd = &c1;    cout << "Using object directly: \n\n";    c1.Report();    c2.Report();    cout << "\n\nUsing type cd* pointer to object : \n\n";    pcd->Report();    pcd = &c2;    pcd->Report();    cout << "\n\nCalling a function with a Cd reference argument: \n\n";    Bravo(c1);    Bravo(c2);    cout << "\n\nTesting assigment: \n\n";    Classic copy;    copy = c2;    copy.Report();    system("pause");    return 0;}void Bravo(const Cd&disk){    disk.Report();}

第三题：修改DMA的示例程序，使其中的三个类都由ABC类派生而来，并在定义中添加vitural View()方法处理数据显示

//file1 threehead.h#ifndef THREEHEAD_H_#define THREEHEAD_H_#include<iostream>using std::cout;using std::endl;using std::cin;class ABC{private:    char *label;    int rating;public:    ABC(){};    ABC(char *l, int r)    {        label = l;        rating = r;    };    ABC(const ABC & D)    {        label = D.label;        rating = D.rating;    };    virtual ~ABC(){ };    virtual void View()const = 0;protected:    char *la()const { return label; };    int ra()const  { return rating; };};class DMA:public ABC{public:    DMA(){};    DMA(const DMA & D) :ABC(D){};    DMA(char *l, int r) :ABC(l,r){};    virtual ~DMA(){};    virtual void View()const;};class LackDMA :public ABC{private:    char color[40];public:    LackDMA(){};    LackDMA(char *s, char *l, int r) :ABC(l, r)    {        strncpy_s(color, s, 39);        color[39] = '\0';    }    virtual ~LackDMA(){};    virtual void View()const;};class HasDMA :public ABC{private :    char * style;public:public:    HasDMA(){};    HasDMA(char *s, char *l, int r) : ABC(l, r)    {        style=s;    }    virtual ~HasDMA(){};    virtual void View()const;};#endif

//file2 threehead.cpp#include"threehead.h"void DMA::View()const{        cout << "---DMA---"<<endl;        cout << "Lable  : " << la() << endl;        cout << "Rating : " << ra() << endl;}void LackDMA::View()const{        cout << "---LackDMA---" << endl;        cout << "Lable  : " << la() << endl;        cout << "Rating : " << ra() << endl;        cout << "Clolr  : " << color << endl;}void HasDMA::View()const{    cout << "---HasDMA---" << endl;    cout << "Lable  : " << la() << endl;    cout << "Rating : " << ra() << endl;    cout << "Style  : " << style << endl;}

//file3 three.cpp#include"threehead.h"#include<string>using namespace std;void readf(int); char s1[40]; char s2[40]; int  i1;int main(){       int kind;    DMA a;    LackDMA b;    HasDMA c;    cout << "Choose class 1 ,2 , 3 to save(q to quit): ";    cin >> kind;    while (cin)    {        if (kind == 1)        {            cout << "MODE 1\n";            readf(kind);            a = DMA(s2, i1);        }        else if (kind == 2)        {            cout << "MODE 2\nEnter color: ";            readf(kind);            b = LackDMA(s1, s2, i1);         }        else if (kind==3)        {            cout << "MODE 3\nEnter style: ";            readf(kind);            c = HasDMA(s1, s2, i1);         }           else        {            break;        }        cout << "Choose class 1 ,2 , 3 to save(q to quit): ";        cin >> kind;    }    a.View();    b.View();    c.View();    cout << "Done!"<<endl;    return 0;}void readf(int i){    cin.get();    if (i == 1)    {        cout << "Enter lable: ";        cin.getline(s2, 30);        cout << "Enter rating: ";        cin >> i1;    }    else    {        cin.getline(s1, 30);        cout << "Enter lable: ";        cin.getline(s2, 30);        cout << "Enter rating: ";        cin >> i1;    }}

第四题：修改实例程序，补全类，补全定义

//file1 fourhead.h#ifndef FOURHEAD_H_#define FOURHEAD_H_#include<iostream>using namespace std;class Port{public:    Port(char * br="none",char *st="none",int b=0);    Port(const Port&p);    //virtual ~Port(){ delete[] brand; };    Port & operator =(const Port &p);    Port & operator +=(int b);    Port & operator -=(int b);    int BottoleCount()const{ return bottles; };    virtual void Show()const;    friend ostream &operator<<(ostream &os,const Port &p);private:    char *brand;    char style[20];    int bottles;};class VintagePort:public Port{private:    char *nickname;    int year;public:    VintagePort(){};    VintagePort(char * br, int b, char *nn, int y);    VintagePort(const VintagePort &vp);    //~VintagePort(){ delete[] nickname; };    VintagePort &operator=(const VintagePort &vp);    void Show()const;    friend ostream & operator<<(ostream & os, const VintagePort &vp);};#endif

//file2 fourhead.cpp#include"fourhead.h"// Port methodPort::Port(char * br, char *st, int b){    brand = br;    int len = strlen(st);    int i = 0;    for (; i < len&&i < 19; i++)        style[i] = st[i];    style[i] = '\0';    bottles = b;}Port::Port(const Port&p){    brand = p.brand;    strcpy_s(style, p.style);    bottles = p.bottles;}Port & Port::operator =(const Port &p){    brand = p.brand;    strcpy_s(style, p.style);    bottles = p.bottles;    return *this;}Port &Port:: operator +=(int b){    bottles += b;    return *this;}Port &Port:: operator -=(int b){    if (bottles >= b)        bottles -= b;    else        cout << "Don,t have so many bottles!";    return *this;}void Port::Show()const {     cout << "Brand: " << brand << endl;    cout << "Kind: " << style << endl;    cout << "Brand: " << bottles << endl;}ostream &operator<<(ostream &os, const Port &p){    os << p.brand << ", " << p.style << ", " << p.bottles;    return os;}// VintagePort methodVintagePort::VintagePort(char * br, int b, char *nn, int y) :Port(br, "vintage", b) {    nickname = nn;    year = y;}VintagePort::VintagePort(const VintagePort &vp) : Port(vp){    nickname = vp.nickname;    year = vp.year;}VintagePort &VintagePort::operator=(const VintagePort &vp){    Port::operator=(vp);    nickname = vp.nickname;    year = vp.year;    return *this;}void VintagePort::Show()const{    cout << "---VintgaePort---\n";    Port::Show();    cout << "Nickname: " << nickname<<endl;    cout << "Year: " << year<<endl;}ostream & operator<<(ostream & os, const VintagePort &vp){    os << Port(vp);    cout << ", " << vp.nickname << ", " << vp.year;    return (os);}

//file3 four.cpp#include"fourhead.h"#include<iostream>int main(){    Port port1("por", "tawny", 20);    cout << port1<<endl;    port1.Show();    VintagePort vp("vpor", 24, "nice", 16);    cout << vp <<  endl;    vp.Show();    VintagePort vp3;    vp3 = vp;    cout << vp3 << endl;    port1 +=1;    cout << "port1 += 1: "<<port1.BottoleCount() << endl;    port1 -= 15;    cout << "port1 -= 15: " << port1.BottoleCount() << endl;    return 0;}

第十二章还是要补全的，接下来补第十二章。。。