如何返回有效的JSON对象？

Question

I'm just getting into php and I have an issue with the return of a JSON object.

Here's the code:

$stmt->bind_result($image_link, $start_time, $end_time, $viet_performer, $english_performer, $viet_event, $english_event, $day, $stage);

            while($stmt->fetch())
            {
                echo json_encode([["image_link" => $image_link,"start_time" => $start_time, "end_time" => $end_time, "viet_performer" => $viet_performer,
                                "english_performer" => $english_performer, "viet_event" => $viet_event, "english_event" => $english_event, "day" => $day,
                                "stage" => $stage]]);

                $stmt->bind_result($image_link, $start_time, $end_time, $viet_performer, $english_performer, $viet_event, $english_event, $day, $stage);
            }

This basically outputs:

{"image_link":"schedule_music.jpg","start_time":"17:00","end_time":"18:30","viet_performer":"","english_performer":"","viet_event":"","english_event":"Tet Music","day":0,"stage":1} {"image_link":"schedule_music.jpg","start_time":"11:00","end_time":"12:00","viet_performer":"","english_performer":"","viet_event":"Nh?c","english_event":"Music","day":1,"stage":0}

//repeat again

However, according to a JSON validator, it's an invalid JSON object.

I would like to produce a valid JSON like so:

[{"image_link":"schedule_music.jpg","start_time":"17:00","end_time":"18:30","viet_performer":"","english_performer":"","viet_event":"","english_event":"Tet Music","day":0,"stage":1},{"image_link":"schedule_music.jpg","start_time":"11:00","end_time":"12:00","viet_performer":"","english_performer":"","viet_event":"Nh?c","english_event":"Music","day":1,"stage":0}]

Notice the start/end brackets as well as a comma separator.

How can I achieve this?

Here is a better example (found somewhere) of how my output similarly looks like:

{
    "id": "a1",
    "session": "General",
    "name": "Exhibitor Setup Begins",
    "startTime": "0900",
    "details": "9am Exhibitor Hall",
    "png": "image",
    "speaker1": "Johnson",
    "speaker2": "Nelson",
    "speaker3": ""
}{
    "id": "b1",
    "session": "General",
    "name": "Conference Registration",
    "startTime": "1000",
    "details": "10am Noon Upper Level Lobby",
    "png": "image",
    "speaker1": "Jackson",
    "speaker2": "",
    "speaker3": ""
}

And how I would like to have the output look like:

[
    {
        "id": "a1",
        "session": "General",
        "name": "Exhibitor Setup Begins",
        "startTime": "0900",
        "details": "9am Exhibitor Hall",
        "png": "image",
        "speaker1": "Johnson",
        "speaker2": "Nelson",
        "speaker3": ""
    },
    {
        "id": "b1",
        "session": "General",
        "name": "Conference Registration",
        "startTime": "1000",
        "details": "10am Noon Upper Level Lobby",
        "png": "image",
        "speaker1": "Jackson",
        "speaker2": "",
        "speaker3": ""
    }
]

Answer 1

Regarding your updated code, the problem is that you are encoding each piece separately rather than encoding all of the data at once. Try this:

$stmt->bind_result($image_link, $start_time, $end_time, $viet_performer, $english_performer, $viet_event,
    $english_event, $day, $stage);

$data = [];
while ($stmt->fetch()) {
    $data[] = [
        "image_link"        => $image_link,
        "start_time"        => $start_time,
        "end_time"          => $end_time,
        "viet_performer"    => $viet_performer,
        "english_performer" => $english_performer,
        "viet_event"        => $viet_event,
        "english_event"     => $english_event,
        "day"               => $day,
        "stage"             => $stage
    ];
}

echo json_encode($data);

---

Response based on earlier version of the question:

It looks like you want an array of objects:

echo json_encode([
    [
        "image_link"        => $image_link,
        "start_time"        => $start_time,
        "end_time"          => $end_time,
        "viet_performer"    => $viet_performer,
        "english_performer" => $english_performer,
        "viet_event"        => $viet_event,
        "english_event"     => $english_event,
        "day"               => $day,
        "stage"             => $stage
    ]
]);

Note that an array containing string keys is going to be converted to an object by json_encode. In the above code, the inner array becomes an object while the outer array does not.

---

This may be a more intuitive way to look at it:

$objectOne = (object) [
    "image_link"        => $image_link,
    "start_time"        => $start_time,
    "end_time"          => $end_time,
    "viet_performer"    => $viet_performer,
    "english_performer" => $english_performer,
    "viet_event"        => $viet_event,
    "english_event"     => $english_event,
    "day"               => $day,
    "stage"             => $stage
];

$objectTwo = (object) [
    "image_link"        => $image_link,
    "start_time"        => $start_time,
    "end_time"          => $end_time,
    "viet_performer"    => $viet_performer,
    "english_performer" => $english_performer,
    "viet_event"        => $viet_event,
    "english_event"     => $english_event,
    "day"               => $day,
    "stage"             => $stage
];

echo json_encode([$objectOne, $objectTwo]);