标签：
http://stackoverflow.com/questions/2391679/why-do-we-need-virtual-methods-in-c
Basic idea: when mark a method as virtual in a parent class, the compiler will check the method in the child class firstly.
why do we need virtual methods in C++?
标签：
原文地址：http://www.cnblogs.com/miaoz/p/4437568.html
