53 C++ - 虚析构函数

class People{
public:
  People(){
    cout << "构造函数 People!" << endl;
  }
  virtual void showName() = 0;
  virtual ~People(){
    cout << "析构函数 People!" << endl;
  }
};
class Worker : public People{
public:
  Worker(){
    cout << "构造函数 Worker!" << endl;
    pName = new char[10];
  }
  virtual void showName(){
    cout << "打印子类的名字!" << endl;
  }
  ~Worker(){
    cout << "析构函数 Worker!" << endl;
    if (pName != NULL){
      delete pName;
    }
  }
private:
  char* pName;
};
void test(){
  People* people = new Worker;
  people->~People();
}

//非纯虚析构函数
class A{
public:
  virtual ~A();
};
A::~A(){}
//纯析构函数
class B{
public:
  virtual ~B() = 0;
};
B::~B(){}
void test(){
  A a; //A类不是抽象类，可以实例化对象
  B b; //B类是抽象类，不可以实例化对象
}