c++ 初学者 简单的 对象数组

#include<iostream>
using namespace std;
class book
{
public:
book(int a,int b):qu(a),price(b){}
int show()
{
return qu*price;
}
private:
int qu,price;
};
int main()
{
book ob[5]={
book(1,10),book(2,20),book(3,30),book(4,40),book(5,50)
};
book *oa=&ob[4];

for(int i=0;i<5;i++)
{
cout<<oa->show()<<"  ";
oa--;
}
return 0;
}