构造函数简单示意

#include <iostream>
using namespace std;

class A{
public:
A();
};

A::A()
{
cout << "call A()" << endl;
}

int main()
{
A a1;
A a[3];

A* p1 = new A;
A* p2 = new A[3];

delete p1;
delete[] p2;

return 0;
}