1.检查错误。

代码：

#include <iostream>using namespace std;class Time
{
private:/* data */
public:Time(/* args */);~Time();void set_time(void);void show_time(void);int hour;int minute;int sec;
};Time::Time(/* args */)
{
}Time::~Time()
{
}Time t;int main() {t.set_time();//成员函数，需要通过对象来调用t.show_time();return 0;
}void Time::set_time(void) {//成员函数，定义的时候需要添加类名来说明cin >>t.hour;cin >>t.minute;cin >>t.sec;
}void Time::show_time(void) {cout <<t.hour <<":" <<t.minute <<":" <<t.sec <<endl;
}

输出结果：

2.成员函数的私有化，定义成员函数。

代码：

 

#include <iostream>using namespace std;class Time
{
private:int hour;int minute;int sec;
public:Time(/* args */);~Time();void set_time(void) {cin >>hour;cin >>minute;cin >>sec;}void show_time(void) {cout <<hour <<":" <<minute <<":" <<sec <<endl;}
};Time::Time(/* args */)
{
}Time::~Time()
{
}Time t;int main() {t.set_time();t.show_time();return 0;
}

输出结果：

3.类内声明，类外实现成员函数。

代码：

9_3.cpp

#include "Student.h"int main() {Student stu;stu.set_value();stu.display();return 0;
}

student.cpp

#include <string>
#include <iostream>using namespace std;
class Student
{
private:int num;string name;char sex;
public:void display();void set_value();};inline 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;
}

输出结果：

4成员函数的声明和实现分离

代码：

9_4.cpp

#include "Student.h"int main() {Student stu;stu.set_value();stu.display();hello();return 0;
}

Student.cpp

#include "Student.h"//<>is not fitvoid Student::display() {cout << "num = " << num << endl;cout << "name = " << name << endl;cout << "sex = " << sex << endl; 
}void Student::set_value() {cin >> num;cin >> name;cin >> sex;
}void hello() {cout <<"Hello world1" <<endl;
}

Student.h

#include <string>
#include <iostream>using namespace std;
class Student
{
private:int num;string name;char sex;
public:void display();void set_value();};

输出结果：

6.计算长方体体积

代码：

#include <iostream>using namespace std;class Cube
{
private:int length;int width;int height;
public:Cube(int l, int w, int h);~Cube();int volume();
};Cube::Cube(int l, int w, int h)
{length = l;width = w;height = h;
}Cube::~Cube()
{
}int main() {int a,b,c;cin >> a >> b >> c;Cube c1(a, b, c);cout << "volume = " <<c1.volume() <<endl;cin >> a >> b >> c;Cube c2(a, b, c);cout << "volume = " <<c2.volume() <<endl;cin >> a >> b >> c;Cube c3(a, b, c);cout << "volume = " <<c3.volume() <<endl;}int Cube::volume() {return height*width*length;
}

输出结果：