对象的指针简单应用

/****************************************************
* 文件名：例八
* 功能：对象的指针和对象的引用
* 说明：使用对象指针作为函数的参数可以实现
        参数值的双向传递
* 时间：2011-3-29      --Lzy
/****************************************************/
#include <iostream.h>        //对象指针的使用


class A
{
public:
    A(int = 0, int = 0);
    void display();
private:
    int x, y;
};

A::A(int xx, int yy)
{
     x = xx; y = yy;
}

void A::display()
{
    cout<<"x="<<x<<" y="<<y<<endl;
}

void main()
{
    A a(3, 5), *p;
    p = &a;
    p->display();
}


//对象指针作为函数的参数

#include <iostream.h>
#include <string.h>

class student
{
private:
    char name[10];
    int rollnumber;
    double score[3];

public:
    student(char *strl= "", int a= 01, double s1=0, double s2=0, double s3=0)
    {
        strcpy(name, strl);
        rollnumber = a;
        score[0] = s1;
        score[1] = s2;
        score[2] = s3;
    }
    void dipsplay();
    double GetScore1(){return score[0];}
    double GetScore2(){return score[1];}
    double GetScore3(){return score[2];}
};

void student::dipsplay()
{
    cout<<"Name："<<name<<endl;
    cout<<"Rollnumber："<<rollnumber<<endl;
    cout<<"Score："<<score[0]<<'\t'<<score[1]<<'\t'<<score[2]<<'\t'<<endl;
}

double f (student *p)
{
    double ave;
    ave = (p->GetScore1()+p->GetScore2()+p->GetScore3())/3;
    return ave;
}

void main()
{
    student s1("Lzy", 18, 98, 97, 99);
    student *p = &s1;
    p->dipsplay();
    cout<<"平均成绩："<<f(p)<<endl;
}

//对象数组

#include <iostream.h>

class MyClass
{
private:
    int x, y;

public:
    MyClass(int = 1, int = 1);
    ~MyClass();
    void set(int = 1, int = 1);
    void display();
};

MyClass::MyClass(int xx, int yy)
{
    x = xx;
    cout<<"构造函数被调用"<<endl;
}

MyClass::~MyClass()
{
    cout<<"析构函数被调用"<<x<<" "<<y<<endl;
}

void MyClass::set(int xx, int yy)
{
    x = xx; y = yy;
}

void MyClass::display()
{
    cout<<x<<" "<<y<<endl;
}

void main()
{
    MyClass a[3];
    for (int i = 0; i < 3; i++)
        a[i].set(i*10, i+10);
    for ( i = 0; i < 3; i++)
        a[i].display();

}