用指向基类的指针指向“派生类”对象-小明编程

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

Student::Student(int n,string nam,float s)
{
	num=n;
	name=nam;
	score=s;
}

void Student::display()
{
	cout<<endl<<"num: "<<num<<endl;
	cout<<"name: "<<name<<endl;
	cout<<"score: "<<score<<endl;
}

class Graduate : public Student
{
public:
	Graduate (int ,string , float,float);
	void display();
private:
	float wage;
};

Graduate ::Graduate(int n,string nam,float s,float w):Student(n,nam,s),wage(w){}

void Graduate ::display()
{
	Student ::display();
	cout<<"wage= "<<wage<<endl;
}

int main()
{
	Student stud1(1001,"Li",87.5);
	Graduate grad1(2001,"wang",98.5,1000);
	Student *pt=&stud1;//这里pt指针指向student类对象stud1，
	pt->display();
	pt=&grad1;//由于pt指向student类，所以这里pt指向的是grad1中从基类student中继承的部分。
	pt->display();
	//总结，通过指向基类对象的指针，只能访问派生类中的基类成员，而不能访问派生类增加的成员；
}

#include <iostream>

#include <string>

using namespace std;

class Student

{

public:

Student(int ,string, float);

void display();

private:

int num;

string name;

float score;

};

Student::Student(int n,string nam,float s)

{

num=n;

name=nam;

score=s;

}

void Student::display()

{

cout<<endl<<"num: "<<num<<endl;

cout<<"name: "<<name<<endl;

cout<<"score: "<<score<<endl;

}

class Graduate : public Student

{

public:

Graduate (int ,string , float,float);

void display();

private:

float wage;

};

Graduate ::Graduate(int n,string nam,float s,float w):Student(n,nam,s),wage(w){}

void Graduate ::display()

{

Student ::display();

cout<<"wage= "<<wage<<endl;

}

int main()

{

Student stud1(1001,"Li",87.5);

Graduate grad1(2001,"wang",98.5,1000);

Student *pt=&stud1;//这里pt指针指向student类对象stud1，

pt->display();

pt=&grad1;//由于pt指向student类，所以这里pt指向的是grad1中从基类student中继承的部分。

pt->display();

//总结，通过指向基类对象的指针，只能访问派生类中的基类成员，而不能访问派生类增加的成员；

}

用指向基类的指针指向“派生类”对象

相关推荐

评论抢沙发

热门标签

相关推荐

评论 抢沙发

热门标签

评论抢沙发