array_filter php return key not sequence

Question

I'm using array_filter to search and remove unwanted results I'm not good English, here's how I am doing it:

$obj_Data = [
    [
        "id" => 1,
        "level" => "admin",
        "name" => "jack"
    ],
    [
        "id" => 2,
        "level" => "member",
        "name" => "john"
    ],
    [
        "id" => 3,
        "level" => "member",
        "name" => "jenny"
    ],
    [
        "id" => 4,
        "level" => "member",
        "name" => "whatever"
    ]
];
function filter_callback($element) {
    if ($element["level"] == "member") {
        return TRUE;
    }
    return FALSE;
}

$arr["data"] = array_filter($obj_Data, "filter_callback");
echo json_encode($arr);

it gives me result like:

{
    "data": {
        "1": {
            "id": 2,
            "level": "member",
            "name": "john"
        },
        "3": {
            "id": 4,
            "level": "member",
            "name": "whatever"
        }
    }
}

This is the result I want:

{
    "data": {
        {
            "id": 2,
            "level": "member",
            "name": "john"
        },
        {
            "id": 4,
            "level": "member",
            "name": "whatever"
        }
    }
}

How can I remove "1" and "3"? Cause I can't use loop for it, thanks for reading.

Answer 1

array_filter() retains the used array keys, making the resulting array an object in the context of JSON. Simply re-index the array through array_values() before JSON-encoding it.