Question

How to use virtual function in three level inheritance in C++

Answer 1

#include <iostream>

using std::cout;
using std::endl;

class base {
public:
	virtual void virtual_function() { cout << "class base" << endl; }
};

class derived1 : public base {
public:
	void virtual_function() { cout << "class derived1" << endl; }
};

class derived2 : public derived1 {
public:
};

int main()
{
	base *p, b;
	derived1 d1;
	derived2 d2;

	p = &b;
	p->virtual_function(); 

	p = &d1;
	p->virtual_function(); 

	p = &d2;
	p->virtual_function(); 

	return 0;
}


/*
run:

class base
class derived1
class derived1

*/

 

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Answer 2

#include <iostream>

using std::cout;
using std::endl;

class base {
public:
	virtual void virtual_function() { cout << "class base" << endl; }
};

class derived1 : public base {
public:
	void virtual_function() { cout << "class derived1" << endl; }
};

class derived2 : public derived1 {
public:
	void virtual_function() { cout << "class derived2" << endl; }
};

int main()
{
	base *p, b;
	derived1 d1;
	derived2 d2;

	p = &b;
	p->virtual_function(); 

	p = &d1;
	p->virtual_function(); 

	p = &d2;
	p->virtual_function(); 

	return 0;
}


/*
run:

class base
class derived1
class derived2

*/

 

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