c++虚函数 默认参数

当基类和继承类中的虚函数同时有默认参数时，通过基类引用或指针调用虚函数，默认参数为基类的默认参数

#include <iostream>class A{public:    virtual int get(int val=5)    {        std::cout << "This is A" << std::endl;        return val;    }private:    int a;};class B:public A{public:    int get(int val=8)    {        std::cout << "This is B" << std::endl;        return val;    }};int main(void){    B b;    A& a = b;    std::cout << a.get() << std::endl;        return 0;}

运行结果：

This is B

5