how to convert the output of a PHP into a string to be used in Android?

I have a .php file on the server side that works fine and extracts me results with PDO method. Therefore, when I click the file on the browser, I have no problem.

Yet, I would like this output to be put in a textView in my Android app.

Now, by the end of the php file i added:

print(json_encode(array($output)));

while in MainActivity.class I tried to get this output by parsing it through JSON.

try {
        String s = "";
        JSONArray jArray = new JSONArray(result);

        for(int i=0; i<jArray.length();i++){
            JSONObject json = jArray.getJSONObject(i);

        }

        TextView.setText(s);

Now, how do I end the JSONObject, so that "s" becomes a String that can later be added to the TextView?

Thanks in advance