C++语言程序设计（第四版 郑莉） 第七章部分题解

第七章

第五题感觉题目有点模糊，不懂究竟要干什么

6.

#include

#include

using namespace std;

class Mamal

{

public:

Mamal(){cout << "Calling Mamal construction" << endl;}

~Mamal(){cout << "Destructing Mamal" << endl;}

};

class Dog:public Mamal

{

public:

Dog(){cout << "Calling Dog construction" << endl;}

~Dog(){cout << "Destructing Dog" << endl;}

};

int main()

{

Dog d;

return 0;

}

10.

#include

using namespace std;

class object

{

private:

int Weight;

public:

object()

{

cout << "Constructing object" << endl;

Weight = 0;

}

int GetWeight(){ return Weight;}

void SetWeight(int n){ Weight = n;}

~object() { cout << "Destructing object" << endl;}

};

class box : public object

{

private:

int Height,Width;

public:

box()

{

cout << "Constructing box" << endl;

Height = Width = 0;

}

int GetHeight(){ return Height;}

void SetHeight(int n){ Height = n;}

int GetWidth(){ return Width;}

void SetWidth(int n){ Width = n;}

~box() { cout << "Destructing box" << endl;}

};

int main()

{

box a;

return 0;

}

11.

//这道题我不明白指针的指向，

#include

using namespace std;

class BaseClass

{

public:

void fn1();

void fn2();

};

void BaseClass::fn1()

{

cout << "Calling the base class fn1()" << endl;

}

void BaseClass::fn2()

{

cout << "Calling the base class fn2()" << endl;

}

class DerivedClass : public BaseClass

{

public:

void fn1();

void fn2();

};

void DerivedClass::fn1()

{

cout << "Calling the derived class fn1()" << endl;

}

void DerivedClass::fn2()

{

cout << "Calling the derived class fn2()" << endl;

}

int main()

{

DerivedClass aDerivedClass;

DerivedClass *pDerivedClass = &aDerivedClass;

BaseClass *pBaseClass = &aDerivedClass;

aDerivedClass.fn1();

aDerivedClass.fn2();

pBaseClass->fn1();

pBaseClass->fn2();

pDerivedClass->fn1();

pDerivedClass->fn2();

return 0;

}