如何从$ _POST中提取数组

Question

I am receiving POST data from a form that is an array along with a few other fields. I need to take the array data only and pass it along in a post request of my own to a backend server as json.

The $_POST data looks like this:

Array (
    [smsgte_submit] => Y 
    [alias] => Array (
        [1] => Array ( 
            [name] => mywife
            [number] => 6135552001
            [ssid] => 1 )
        [2] => Array (
            [name] => daughter
            [number] => 6135553001
            [ssid] => ) 
     )
)

I only want to capture the alias entries and encode them in json.

I was successful in encoding the entire $_POST array into json with:

$data['jsonpost'] = json_encode($_POST);

which encoded the array as expected, however, I only want the alias array, so I tried the following:

$data['jsonpost'] = json_encode($_POST['alias']);

That, however doesn't work, it returns null to the server. Then I tried:

$data['jsonpost'] = json_encode(array_filter($_POST, 'alias'));

But that returned null.

Maybe I need to redesign my form, but in the end, I want a json array that looks like this:

    {
    "alias": {
        "name":"mywife",
        "number":"6135552001",
        "ssid":"1"
    },
        "alias": {
        "name":"daughter",
        "number":"6135553001",
        "ssid":"2"
    }
}

Answer 1

It turns out that the following syntax should be correct:

$data['jsonpost'] = json_encode($_POST['alias']);

However, in order to get it to work, I had to split it as follows:

$jsonpost = json_encode($_POST['alias']);
$data['jsonpost'] = jsonpost;

I switched back and forth between the two options a few times, but only the second one works, at least with PHP 7.3.5.