Problem with printing copy constructor OOP - c++

Question

Having trouble with the printing copy constructors elements from Arr s to Arr s1 , also having troubles with << operator it doesn't work, please help cuz I am not pro just a student.
#include <iostream>
using namespace std;
class Arr {
private:
int size;
int *arr;
public:
Arr(int size,int *arr) {
this->size = size;
this->arr = new int [size];
for (int i = 0; i < size ; ++i) {
this->arr[i] = arr[i];
}
}
~Arr() {
delete[] arr;
}
Arr(const Arr &x) {
this->size = x.size;
this->arr = new int[x.size];
for (int i = 0; i < x.size; ++i) {
this->arr = x.arr;
}
}
Arr() : size(0),arr(0) {}
Arr(Arr &&x) {
this->size = x.size;
this->arr = new int[x.size];
for (int i = 0; i < x.size; ++i) {
this->arr = x.arr;
}
}
friend ostream &operator<<(ostream &out, const Arr &t) {
out << t.size;
for (int i = 0; i < t.size; i++) {
out << t.arr[i];
}
return out;
}
friend istream &operator>>(istream &in, Arr &t) {
in >> t.size;
for (int i = 0; i < t.size; ++i) {
in >> t.arr[i];
}
return in;
}
};
int main() {
int size = 3;
int arr [] = {1,2,3};
Arr s1(size,arr);
cin << s1;
cout<<s1;
Arr s(s1);
cout<<s; // not working at all
return 0;
}

Answer 1

You are writing
this->arr = x.arr;
in the copy constructor, rather than
this->arr[i] = x.arr[i];
That is, currently your code is copying the array pointer, not the elements of the array.
When you're debugging, first look over your code to make sure each part is doing what you want it to do and that you didn't make a typo like this. Then, if you don't find the problem, you can use a debugger like gdb to step through your code and monitor the values of the variables to make sure your program is doing what you'd like.