c++面向对象程序设计 谭浩强 第二章答案

类体内定义成员函数
#include <iostream>

using namespace std;
class Time

{

public:

    void set_time();
    void show_time();
private:                    //成员改为公用的

    int hour;
    int minute;
    int sec;
};
void Time::set_time()          //在main函数之前定义

{

    cin >> hour;
    cin >> minute;
    cin >> sec;
}

void Time::show_time()         //在main函数之前定义

{

    cout << hour << ":" << minute << ":" << sec << endl;
}

int main()

{
    Time t1;
    t1.set_time();
    t1.show_time();
    return ;
}

：

2.3 改写2.：类体内声明成员函数，类外定义成员函数
#include <iostream>

using namespace std;
class Time

{
public:

    void set_time(void)

    {
        cin >> hour;
        cin >> minute;
        cin >> sec;
    }

    void show_time(void)

    {
        cout << hour << ":" << minute << ":" << sec << endl;
    }

private: int hour;
         int minute;
         int sec;
};
c++面向对象程序设计 答案

Time t;
int main()

{

    t.set_time();
    t.show_time();
    return ;
}

c++面向对象程序设计 谭浩强

：

#include <iostream>

using namespace std;
class Time

{
public:

    void set_time(void);
    void show_time(void);
private:

    int hour;
    int minute;
    int sec;
};
c++面向对象程序设计 谭浩强

void Time::set_time(void)

{
    cin >> hour;
    cin >> minute;
    cin >> sec;
}

void Time::show_time(void)
{
    cout << hour << ":" << minute << ":" << sec << endl;
}

Time t;
int main()

{
    t.set_time();
    t.show_time();
    return ;
}

：

//xt2-4-1.cpp(main.cpp)

#include <iostream>

using namespace std;
#include "xt2-4.h"

int main()

{
    Student stud;
    stud.set_value();
    stud.display();
    return ;
}

//xt2-4-2.cpp(即student.cpp)

#include "xt2-4.h"                      //在此文件中进行函数的定义

#include <iostream>

using namespace std;                   //不要漏写此行

void Student::display()

{
    cout << "num:" << num << endl;
    cout << "name:" << name << endl;
    cout << "sex:" << sex << endl;
}

void Student::set_value()

{
    cin >> num;
    cin >> name;
    cin >> sex;
}

：

//xt2-5-1.cpp(file1.cpp)

#include <iostream>

#include "xt2-5.h"

int main()

{
    Array_max  arrmax;
    arrmax.set_value();
    arrmax.max_value();
    arrmax.show_value();
    return ;
}

//xt2-5-2.cpp(arraymax.cpp)

#include <iostream>

using namespace std;
#include "xt2-5.h"

void Array_max::set_value()

{
    int i;
    for (i = ; i < ; i++)

        cin >> array[i];
}

void Array_max::max_value()

{
    int i;
    max = array[];
    for (i = ; i<; i++)

    if (array[i]>max)
        max = array[i];
}

void Array_max::show_value()

{
    cout << "max=" << max << endl;
}

：解法一

#include <iostream>

using namespace std;
class Box

{
public:

    void get_value();
    float volume();
    void display();
public:

    float lengh;
    float width;
    float height;
};

void Box::get_value()

{
    cout << "please input lengh, width,height:";
    cin >> lengh;
    cin >> width;
    cin >> height;
}

float Box::volume()

{
    return(lengh*width*height);
}

void Box::display()

{
    cout << volume() << endl;
}

int main()

{
    Box box1, box2, box3;
    box1.get_value();
    cout << "volmue of bax1 is ";
    box1.display();
    box2.get_value();
    cout << "volmue of bax2 is ";
    box2.display();
    box3.get_value();
    cout << "volmue of bax3 is ";
    box3.display();
    return ;
}

解法二：

#include <iostream>

using namespace std;
class Box

{
public:

    void get_value();
    void volume();
    void display();
public:

    float lengh;
    float width;
    float height;
    float vol;
};

void Box::get_value()

{
    cout << "please input lengh, width,height:";
    cin >> lengh;
    cin >> width;
    cin >> height;
}

void Box::volume()

{
    vol = lengh*width*height;
}

void Box::display()

{
    cout << vol << endl;
}

int main()

{
    Box box1, box2, box3;
    box1.get_value();
    box1.volume();
    cout << "volmue of bax1 is ";
    box1.display();
    box2.get_value();
    box2.volume();
    cout << "volmue of bax2 is ";
    box2.display();
    box3.get_value();
    box3.volume();
    cout << "volmue of bax3 is ";
    box3.display();
    return ;
}