看下这个程序

#include<iostream>
using namespace std;
class test
{
public:
    test();
    test(int i,int j);
    ~test()
    {
        cout<<"Destructor called:"<<X<<','<<Y<<endl;
    }
    void set(int i,int j);
    void print()
    {
        cout<<X<<","<<Y<<endl;
    }
private:
    int X,Y;
};
test::test()
{
    X=Y=0;
    cout<<"Default constructor 2332312called"<<endl;
}
test::test(int i,int j)
{
    X=i;
    Y=j;
    cout<<"Constructorcalled:"<<X<<','<<Y<<endl;
}
void test::set(int i,int j)
{
    X=i;
    Y=j;
}
int main()
{
    test*ptr1,*ptr2,*ptr3;
    ptr1=new test(1,2);
    ptr2=new test(3,4);
    ptr3=new test[2];
    ptr3[0].set(5,6);
    ptr3[1].set(7,8);
    ptr1->print();
    ptr2->print();
    ptr3[0].print();
    ptr3[1].print();
    delete ptr1;
    delete ptr2;
    delete []ptr3;
    cin.get();
    cin.get();
    return 0;
}
在这个程序里运行结果是
Constructorcalled:1,2
Constructorcalled:3,4
Default constructor 2332312called
Default constructor 2332312called
1,2
3,4
5,6
7,8
Destructor called:1,2
Destructor called:3,4
Destructor called:7,8
Destructor called:5,6
为什么第三行会出现两次啊，我怎么觉得应该出现一次呢