OOP Vui

//https://www.facebook.com/CungHocLapTrinhUIT/
//Đoạn code 1
#include <iostream>
using namespace std;

class A{
public:
    A(){
        cout << "Constructor A" << endl;
    }
    ~A(){
        cout << "~Destructor A" << endl;
    }
};

class B : public A
{
public:
    B(A &a){
        cout << "Constructor B" << endl;
    }
    ~B(){
        cout << "~Destructor B" << endl;
    }
};

void main(){
    A a;
    B b(a);
}

//Đoạn code 2
#include <iostream>
using namespace std;

class A{
public:
    A(){
        cout << "Constructor A" << endl;
    }
    ~A(){
        cout << "~Destructor A" << endl;
    }
};

class B : public A
{
public:
    B(A a){
        cout << "Constructor B" << endl;
    }
    ~B(){
        cout << "~Destructor B" << endl;
    }
};

void main(){
    A a;
    B b(a);
}