#include?<iostream>
#include?<stdlib.h>
#include?<string>
using?namespace?std;

/**
?*?定義動(dòng)物類：Animal
?*?虛函數(shù)：eat()
?*?純虛函數(shù)：move()
?*?數(shù)據(jù)成員：m_strName
?*/
class?Animal
{
public:
????//?默認(rèn)構(gòu)造函數(shù)
????Animal（）{}
????//?含參構(gòu)造函數(shù)
	Animal(string?name){m_strName?=?name;?cout?<<?"Animal"?<<?endl;}
????//?虛析構(gòu)函數(shù)
	virtual?~Animal(){cout?<<?"~Animal"?<<?endl;}
????//?虛成員函數(shù)
	virtual??void?eat(){cout?<<?"Animal--"?<<?m_strName?<<?"--?eat"?<<?endl;}
????//?純虛函數(shù)
	virtual?void?move()?=?0;
public:
????//?數(shù)據(jù)成員
	string?m_strName;
};

/**
?*?定義狗類：Dog
?*?公有繼承動(dòng)物類
?*?虛成員函數(shù)：eat()、move()
?*/
class?Dog?:?public?Animal
{
public:
????//?默認(rèn)構(gòu)造函數(shù)
????Dog(){}
????//?含參構(gòu)造函數(shù)
	Dog(string?name){m_strName?=?name;?cout?<<?"Dog"?<<?endl;}
????//?虛析構(gòu)函數(shù)
	virtual?~Dog(){cout?<<?"~Dog"?<<?endl;}
????//?虛成員函數(shù)eat()
	virtual?void?eat(){cout?<<?"Dog--"?<<?m_strName?<<?"?--?eat"?<<?endl;}
????//?虛成員函數(shù)move()
	virtual?void?move(){cout?<<?"Dog--"?<<?m_strName?<<?"?--?move"?<<?endl;}
public:
????//?數(shù)據(jù)成員
	string?m_strName;
};

int?main(void)
{
????//?通過動(dòng)物類實(shí)例化狗類
????Dog?a(狗類)；
????Animal?*pa?=?a;
????//?調(diào)用成員函數(shù)
	pa->eat();
????pa->move();
????//?釋放內(nèi)存
	delete?*pa;
	pa?=?NULL;
????
	return?0;
}

Animal的默認(rèn)構(gòu)造函數(shù)只聲明了，沒有定義；

應(yīng)該把“Animal();”改為“Animal(){}”