Problem with chaining operator<< and operator++

I'm learning C++ and I have this problem:

#include <iostream>
using namespace std;


class test
{
    public:
    test(){};
    test(int i):var{i}{};

    test& operator++(){++var; return this;}  
    test  operator++(int dummy){test tmp =*this;var++;return tmp;}

    friend ostream& operator<<(ostream&, const test&);


   private:
   int var;
};

ostream& operator<<(ostream& o, const test& obj)
{
    o<<obj.var;
    return o;
}


int main()
{
    test obj{2};
    cout << obj << endl;
    obj++;
    cout << obj << endl;
    cout << obj <<' '<< ++obj<<endl;

    return 0;
}

the output i expected was: 2 3 3 4

instead i have: 2 3 4 4

if i replace the last increment ++obj with obj++ the situation is even more weird: 2 3 4 3

it's like the stream is read in the opposite way, can you help me?