C++看程序写结果 虚函数、构造、析构、初始化列表

虚函数、构造、析构、初始化列表

#include <iostream>
using namespace std;
class Base{
public:
    Base(const char* p_szName):m_szName(p_szName)  {cout << "Base类构造：" << m_szName << "," << endl;}
    virtual ~Base()  {cout << "Base类析构：" << "~" << m_szName << "," << endl;}
    //~Base()  {cout << "Base类析构：" << "~" << m_szName << "," << endl;}
private:
    const char* m_szName;
};

class Derived:public Base{
public:
    Derived(const char* p_szName):m_szName(p_szName)
    ,m_objA((const char*)"A")
    ,m_objB((const char*)"B")
    ,Base((const char*)"C"){
        cout << "Derived类构造：" << m_szName << "," << endl;
    }
    virtual ~Derived()  {cout << "Derived类析构：" << "~"<< m_szName << "," << endl;}
    //~Derived()  {cout << "Derived类析构：" << "~"<< m_szName << "," << endl;}

private:
    const char* m_szName;
    Base m_objB;
    Base m_objA;
};

int main(){
    Base* p= new Derived("D");
    delete p;
    return 0;
}

先根据继承先后关系，用C完成Base的构造，然后根据Derived成员定义的先后关系，对字符串m_szName、成员m_objB、成员m_objA进行初始化，但是对字符串m_szName初始化并不首先打印，对成员m_objB、成员m_objA初始化会调用Base的构造函数，然后才执行大括号里面的内容

Base类构造：C,
Base类构造：B,
Base类构造：A,
Derived类构造：D,
Derived类析构：~D,
Base类析构：~A,
Base类析构：~B,
Base类析构：~C,