【C++】继承时构造函数和析构函数

#include<iostream>
using namespace std;

class A
{
public:
    A()
    {
        cout << "A 默认构造函数" << endl;
    }
    A(int i)
    {
        cout << "A A(int i)构造函数" << endl;
    }
    ~A()
    {
        cout << "A 析构函数" << endl;
    }
    A(const A & obj)
    {
        cout << "A 复制构造函数" << endl;
    }
};

class B : public A
{
public:
    B()
    {
        cout << "B 默认构造函数" << endl;
    }
    B(int j):A(j)
    {
        cout << "B B(int j):A(j)" << endl;
    }
    ~B()
    {
        cout << "B 析构函数" << endl;
    }
    B(const B & obj)  //调用A的默认构造函数
    {
        cout << "B 复制构造函数" << endl;
    }
    //B(const B & obj):A()  //调用A的默认构造函数
    //{
    //    cout << "B 复制构造函数" << endl;
    //}
    //B(const B & obj):A(obj)  //调用A的复制构造函数
    //{
    //    cout << "B 复制构造函数" << endl;
    //}
};

int main()
{
    {
        cout << "----------------------" << endl;
        B b;
        cout << "----------------------" << endl;
        B b1(3);
        cout << "----------------------" << endl;
        B b2(b);
        cout << "----------------------" << endl;
    }
    return 0;
}