a.h

it can help you use C++ program we

// a.h，类A、B和C的定义及实现
#include <iostream >
using namespace std;

class A
{
public:
	void Display() {
		cout << "A::Display()\n";
	}
};

class B : public A
{
public: 
	void Display() {   //重载基类A的Display( )函数
		cout <<"B::Display()\n";
	}
};

class C : public A
{
public:
	void Display() {   //重载基类A的Display( )函数
		cout <<"C::Display()\n";
	}
};