C++primer plus第六版课后编程题答案13.1

Cd.cpp

#include <iostream>
#include <cctype>
using namespace std;

class Cd{

private:
char performers[50];
char label[20];
int selections;
double playtime;
public:
char *perfor(){return performers;};
char *lab(){return label;};
int sel(){return selections;};
double play(){return playtime;};
//为了Classic的=
void setPer(char *p){ strcpy(performers,p);};
void setlab(char *l){strcpy(label,l);};
void setsel(int num){selections=num;};
void setplay(double s){playtime=s;};
//
Cd(char *s1,char *s2,int n,double x)
{
strcpy(performers,s1);
strcpy(label,s2);
selections=n;
playtime=x;
}
Cd(const Cd &d)
{
strcpy(performers,d.performers);
strcpy(label,d.label);
selections=d.selections;
playtime=d.playtime;
}
Cd(){}
virtual ~Cd(){}//构造函数应为虚函数
virtual void Report()const
{
cout<<"performers:"<<performers<<endl;
cout<<"label:"<<label<<endl;
cout<<"selection:"<<selections<<" playtime:"<<playtime<<endl;
//cout<<endl;
}
virtual Cd&operator=(const Cd &d)
{
return Cd(d);
}
};
class Classic:public Cd
{
private:
char mainLabel[50];
public:
Classic(char *s1,char *s2,char *s3,int n,double x):Cd(s1,s2,n,x)
{
strcpy(mainLabel,s3);
}
Classic(Classic &c):Cd(c.perfor(),c.lab(),c.sel(),c.play())//不能使用const
{
//char *per=c.perfor();
//strcpy(performers,c.perfor());
strcpy(mainLabel,c.mainLabel);
}
Classic(){}
virtual ~Classic(){}
virtual void Report()const
{
Cd::Report();//原来是这样子调用父类的方法的啊
cout<<"mainLabel:"<<mainLabel;
cout<<endl;
}
/*
Classic &operator=(Classic &c)//不能使用const
{
return Classic(c);
}*/
void operator=(Classic &c)//不能使用const
{
//strcpy(performers,c.perfor());
Cd::setPer(c.perfor());
Cd::setlab(c.lab());
Cd::setsel(c.sel());
Cd::setplay(c.play());
strcpy(mainLabel,c.mainLabel);
}

};


main131.cpp
#include <iostream>
#include "Cd.cpp"
using namespace std;
void Bravo(const Cd &d)
{
d.Report();
};
void main131()
{
Cd c1("Beates","Capitol",14,35.5);
Classic c2=Classic("Piano Sonata in B flag,Fantasia in C","Alfred Brendel","Philips",2,57.17);
Cd *pcd=&c1;

cout<<"Using object directly:"<<endl;
c1.Report();
cout<<endl;
c2.Report();

cout<<"Using type cd * pointer to object:"<<endl;
pcd->Report();
cout<<endl;
pcd=&c2;//重定位pcd
pcd->Report();

cout<<"Calling a funciton with a Cd reference argument:"<<endl;

Bravo(c1);
Bravo(c2);

cout<<"Testing assignment:"<<endl;
//Classic copy=c2;//这样也是可以的
//Classic copy(c2);//这样就没问题，那就是赋值出了问题
Classic copy; //因为这里已经初始化了，所以copy已经是利用Classic()初始化了
copy=c2;//这里有问题、//这样的话，这样赋值就不能返回一个Classic的值了
copy.Report();
cin.get();

}