Can't parse DialogFlow json response

Question

I know this question has been asked multiple times... but I can't figure out what happens I've an issue while trying to parse a json response. Here is the json (extract)

{"result":{"fulfillment":{"speech":"[{\"name\":\"Pallet truck\",\"object_type\":\"machine\",\"object_id\":3279}, ...

I'm applying JSON parse on it like this

 var obj = JSON.parse(response);

Then I have something like this

"result":{
  "fulfillment":{
     "speech":"[
{"name":"Pallet truck","object_type":"machine","object_id":3279},        
{"name":"CollaborativeRobot","object_type":"machine","object_id":3273},
{"name":"Bender","object_type":"machine","object_id":3997},...

I want only display it like that at the end :

Name : Pallet Truck
Name : CollaborativeRobot
Name : Bender

I've tried things like this

for (var key in obj.result.fulfillment.speech) {
      if (obj.result.fulfillment.speech.hasOwnProperty(key)) {
            console.log(obj.result.fulfillment.speech[key].name.val());
      }
}

But I only got undefined results... I think I'm missing something while accessing the array (it's been a while without coding anything in php/js )

EDIT

EDIT 2

It seams that the issue is on server side, while double encoding here is an extract :

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'http://api.mephisto.optimdata.io/search?object_type=machine');
    curl_setopt($ch, CURLOPT_USERPWD, "$login:$password");
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json', 'authorization: JWT '.$accessToken));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $result = curl_exec($ch);
    curl_close($ch);

    $fulfillment = new stdClass();
    $fulfillment->speech = $result;
    $result = new stdClass();
    $result->fulfillment = $fulfillment;
    $result->requete = "machines actives";
    $responseQueryAPI = new stdClass();
    $responseQueryAPI->result = $result;
    echo json_encode($responseQueryAPI);

Maybe this is because the curl response is already json? The curl response looks like this :

[
    {
        "name": "Pallet truck",
        "object_type": "machine",
        "object_id": 3279
    },
    {
        "name": "Collaborative Robot",
        "object_type": "machine",
        "object_id": 3273
    },
    {
        "name": "Bender",
        "object_type": "machine",
        "object_id": 3997
    },

Answer 1

name is just a string, so try to replace

for (var key in obj.result.fulfillment.speech) {
    if (obj.result.fulfillment.speech.hasOwnProperty(key)) {
        console.log(obj.result.fulfillment.speech[key].name.val());
    }
}

to

for (var i = 0; i < obj.result.fulfillment.speech.length; ++i) {
    console.log(obj.result.fulfillment.speech[i].name);
}

Edit:

The response data looks wrong.

I got syntax error with JSON.parse('{"result":{"fulfillment":{"speech":"[{\\"name\\":\\"Pallet truck\\",\\"object_type\\":\\"machine\\",\\"object_id\\":3279}]"}}}'); .

Try to use JSON.parse('{"result":{"fulfillment":{"speech":[{"name":"Pallet truck","object_type":"machine","object_id":3279}]}}}'); .