Using constructor initializer list to initize Reference Variable

Hi i am trying to understand how classes are compiled in C++. And so creating different examples to understand initialization rules(along with theory from books). My example code is as follows:

#include <iostream>
using namespace std;
class NAME{
    public:
    
    NAME(int p):x(r){
        cout<<x<<endl;
    }
    int &x;
    int r=3;  
};
int main()
{
    
NAME obj(4);
    return 0;
}

My question is that does the order in which i have specified the data members &x and int r =3; matter? I have checked by reversing the order of those two and still the program works . I have read that compilaion of classes happens in two steps:

1. All member declarations are compiled.
2. Then function bodies are complied.

Now my question is according to this rule the declarations of reference type x should happend first(since compilation hppens in order of variable declartion/definition) and then int type r should happen .And then constructor bodies should be compiled.But since we must always initialize a reference type, how is this program working when we have not intialize x? Also i know that constructor initializer list are used to initialize x from r. I think i am getting confused about the fact that **when we use initializer list then will the in-class declaration will happen first or the constructor list will directly initialize the members? ** If it is the latter then why does the order of arguments in the initializer list matters?