C++虚函数的使用。一个代码

Question

#include <iostream> 
using namespace std;   
class Base{   
public:   
    Base(){}     
    virtual void g(int i=10){
        cout<<"Base::g()"<<i<<endl;
    }  
};   
class Derived : public Base{   
public:   
    Derived(){}
    void g(int i = 20){
        cout<<"Derived::g()"<<i<<endl;
    }
};   
int main()   {   
    Base *pb = new Derived;   
    pb->g();
    return 0;
}  

输出

Derived::g()10

为什么不是Derived::g()20？？？

Answer 1

参考https://blog.csdn.net/zhuimengzh/article/details/6787682