Function params pass Objects by reference, but..

I was doing this problem in javascript:

To write a function which can convert an array like [1,2,3] to a linked list style of data structure like:

{ value: 1, 
  rest: 
    { value: 2, 
      rest: 
       { value: 3,  
        rest: null 
       }
    } 
}        

And vice-versa - which can take a object like above and convert it into an array.

While doing the second problem: this is what I wrote:

function listToArray(list) {
  const array = [];
  while (list) {
    array.push(list.value);
    list = list.rest;
  }
  return array;
}        

In Line number 5

list = list.rest;        

I though about it for a minute and this is a slightly tricky line - because we all know that arrays and objects in javascript are passed by reference and the though lingered in my head for a second that won't it change the original list to list.rest.

But then it dawned upon me, list is a variable or a binding to that object and if I try to mutate that object by using the list variable like this:

list.x = "Prabhas"        

then it will surely mutate that object - but if i try to assign something new to the "list" variable - then that doesn't really care about the object being passed by reference - and I was planning to create a deep copy of the list object and store it in a new variable - but I avoided that.

And yes the function works as expected.

You might wonder about why I choose the image of an octopus for this article - it's because of this analogy about the tentacles of an octopus trying to be bindings to various values in js.