C++类继承示例

C++的子类与孙子类都实现了虚函数时，孙子类的实现会覆盖掉子类的实现。

继承的最主要的应用就是把不同的类放到一个数组中，然后遍历调用同名函数。

实例如下：

#include <iostream>

#include <stdlib.h>

#include <vector> 

using namespace std;



class Parent{

	protected:

		string pname;

	public:

		Parent(string name){

			pname=name;	

		}

		

		virtual void printName(){};

};



class Child: public Parent{

	protected:

		string cname;

	public:

		Child(string name):Parent(name){

			cname=name;

		}

	

		virtual void printName(){

			cout<<"This is child, cname is "<<cname<<", pname is "<<pname<<endl;

		}

};



class GrandChild: public Child{

	private:

		string gname;

		

	public:

		GrandChild(string name):Child(name){

			gname=name;

		}

		

		virtual void printName(){

			cout<<"This is grandchild, gname is "<<gname<<", cname is "<<cname<<", pname is "<<pname<<endl;

		}

};



int main(){

	string name="C";

	Child child(name);

	name="GC";

	GrandChild gchild(name);

	

	vector<Parent*> mlist;

	mlist.push_back(dynamic_cast<Parent*>(&child));

	mlist.push_back(dynamic_cast<Parent*>(&gchild));

	

	for(int i=0;i<mlist.size();++i){

		mlist[i]->printName();

	}

}

 

注意子类与孙子类的printName函数前的virtual可加可不加，都可以正确运行……不知道哪个才是正确写法= =