派生类中实现类的基本函数

如何在派生类中实现类的基本函数：

1，  首先要在派生类中的构造函数中调用基类的构造函数

2，  基类与派生类的析构函数一定要为虚函数

class Base{public:Base& operator=(const Base &base);virtual ~Base()        //申明为虚函数{cout<<"~Base"<<endl;}private:int b_x, b_y, b_z;};class Derived: public Base{public:Derived& operator=(const Derived &derived);virtual ~Derived()     //申明为虚函数{cout<<"~Derived"<<endl;}private:int d_i, d_j, d_k;};Derived& Derived::operator=(const Derived &derived){if (this == &derived){return *this;}Base::operator=(derived);    //调用基类的构造函数初始化基类成员变量d_i = derived.d_i;d_j = derived.d_j;d_k = derived.d_k;return *this;}int main(void){Base *p = new Derived;delete p;return 0;}

运行结果：

如果不申明为虚函数的话，那么就只能析构基类，不能析构派生类。