注意类的虚函数的一个用法

#include <iostream>
using namespace std;

class A
{
public:
	A()
	{
		cout<<"A Create!"<<endl;
	}
	~A()
	{
		cout<<"delete A!"<<endl;
	}
	virtual void fun1()
	{
		cout<<"A fun1()"<<endl;
	}

	void fun2()
	{
		cout<<"A fun2()"<<endl;
		fun1();
	}
};

class B : public A
{
public:
	B()
	{
		cout<<"B Create!"<<endl;
	}
	~B()
	{
		cout<<"delete B!"<<endl;
	}
	virtual void fun1()
	{
		cout<<"B fun1()"<<endl;
	}
};

void main()
{
	B testb;
	testb.fun2();
}

上述代码输出：

A Create!
Create BBBBBBBBBBB
A fun2
B fun1
delete BBBBBBBB
delete A!
Press any key to continue

如果fun1()函数为非虚函数时输出如下：

A Create!
B Create!
A fun2()
A fun1()
delete B!
delete A!
Press any key to continue