#include<iostream.h>
class animal
{
public:
animal()
{
cout<<"animal construct"<<endl;
}
~animal()
{
cout<<"construct animal"<<endl;
}
virtual void breath() //virtual定義虛函數
{
cout<<"bubble2"<<endl;
}
};
class fish:public animal //只調用animal中的animal（）
{
public:
fish()
{
// cout<<"hello world"<<endl;
}
~fish()
{
// cout<<"construct helllo world"<<endl;
}
void breath()
{
//animal::breath();
//cout<<"fish bubble"<<endl;
}
};
void fn(animal *pan)
{
pan->breath();
}
void main()
{
fish fh;
//st.breath ();//如果子類和基類有兩個同名函數，則最后用子類覆蓋基類，這叫重載。
animal *pan;
pan=&fh; //改變指針，把animal的指針用fish替換了。但是還是輸出animal。若在animal前加virtual虛擬，則輸出fish
fn(pan);
}