关于delete 和 new

// new_test.cpp

#include<iostream>

using namespace std;

class A
{
public:
    A()
    {
        cout << "A()" << endl;
    }
    int data;
};

class B
{
public:
    int data;
};

int main()
{

    A *a1 = new A;
    cout << "a1->data = " << a1->data << endl;

    A *a2 = new A();
    cout << "a2->data = " << a2->data << endl;

    cout << "----- 以下没有提供默认构造 -----" << endl;
    
    B *b1 = new B;
    cout << "b1->data = " << b1->data << endl;
    
    B *b2 = new B();
    cout << "b2->data = " << b2->data << endl;
    

    return 0;
}