面向对象设计C---友元类 实验（二十三）

目的：
   
    掌握 友元类 的使用方法

#include <iostream>
#include <cstring>  //在 vc6.0 下 使用#include<string.h>
           //在 g++ 环境 为 cstring

using namespace std;
class CStudent
{
  public:
    CStudent();//构造函数 没有返回值
    CStudent(char *name,int age); //定义一个带参 构造函数
    ~CStudent();         //析构函数，唯一，不能重载
    CStudent(const CStudent &student);

    friend class CTeacher;

    CStudent &init(char *name,int age);         //赋值功能
    void  output();            //输出类对象的两个数据成员
  private:
    char name[20];
    int  age;
};

CStudent::CStudent()  //无参构造函数
{
    strcpy(this->name," ");
    this->age=0;
}

CStudent::CStudent(char *name,int age)  //带参 构造函数实现
{
    strcpy(this->name,name);
    this->age=age;
}

CStudent::CStudent(const CStudent &student)
{
    strcpy(this->name,student.name);
    this->age = student.age;
}

CStudent::~CStudent()
{
    cout<<"the object is deconstructing..."<<endl;
}

CStudent &CStudent::init(char *name,int age)
{
    strcpy(this->name,name);
    this->age=age;
    return (*this);
}

void CStudent::output()
{
    cout<<this->name<<"      "<<this->age<<endl;
}

/*--------------------------------------------------*/
class CTeacher
{
public:
    CStudent &visit(CStudent &student,char *name,int age);
};

CStudent &CTeacher::visit(CStudent &student,char *name,int age)
{
    strcpy(student.name,name);
    student.age = age;
    return student;
}
/*--------------------------------------------------*/

int main()
{
    CStudent stu1;
    CTeacher teacher1;
    teacher1.visit(stu1,"tom",23);
    stu1.output();
    return 0;
}

ywx@yuweixian:~/yu/c++/shiyan1$ ./student2
tom      23
the object is deconstructing...
ywx@yuweixian:~/yu/c++/shiyan1$