Undefined index: faceId in <b>/storage/ssd1/900/12273900/public_html/upload_image.php</b> on line <b>30

Question

I'm trying to parse JSON and extract a specific key, called faceId from it using PHP. But, when I try to parse it, I face the following error.

<b>Notice</b>:  Undefined index: faceId in <b>/storage/ssd1/900/12273900/public_html/upload_image.php</b> on line <b>30</b><br />
I/flutter (18628): <br />

here's my JSON

[
{
    "faceId": "a1e0ee95-3365-40b0-91f2-e0a05bdeadcc",
    "faceRectangle": {
        "top": 158,
        "left": 298,
        "width": 226,
        "height": 226
    },
    "faceAttributes": {
        "age": 19.0
    }
}]

This is how I'm trying to parse it but it always throws the error.

$data = array('image' => $imageUrl);


$options = array(
'http' => array(
'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
'method'  => 'POST',
'content' => http_build_query($data),
),
);

$context  = stream_context_create($options);

$result1 = file_get_contents($url, true, $context);



$jsonFaceID = json_decode($result1,true);
$finalFaceID= $jsonFaceID['faceId'];//the error appears here.

I've tried it another way too but still the same error.

$jsonFaceID = json_decode($result1,false);//it returns a JSON object
$finalFaceID= $jsonFaceID->faceId;

I'm unable to get the logic behind the error. Any help would be really appreciated. Thanks a lot

I am getting the result through a POST request from MS Face API for detect_face.

Answer 1

That json is an object in an array

Array
(
    [0] => stdClass Object
        (
            [faceId] => a1e0ee95-3365-40b0-91f2-e0a05bdeadcc
            [faceRectangle] => stdClass Object
                (
                    [top] => 158
                    [left] => 298
                    [width] => 226
                    [height] => 226
                )

            [faceAttributes] => stdClass Object
                (
                    [age] => 19
                )
        )
)

So the code should be

$finalFaceID= $jsonFaceID[0]->faceId;