C++虚函数例子

class a
{ 
public:
 a()
 {
  int jj = 0;
 }
 virtual void print()
  //void print()
 {
  cout <<1<<endl;
 }
};

class b:public a
{ 
public:
 virtual void print()
 {
  cout <<2<<endl;
 }
};

class c:public b
{ 
public:
 void print()
 {
  cout <<3<<endl;
 }
};

int main()
{
 a varA;
 varA.print();

 a* pa;
 pa = new b;
 pa->print();

 pa = new c;
 pa->print();

 b *pb;
 pb = new c;
 pb->print();

 return 0;
}