array_push（）期望参数1是带有json文件的数组

Question

I want to combine two array's together so I can add that to a json file what already exists.

I've tried to use array_push() but I keep getting the same error that the existing decoded json file is not an array but an object.

$new_user = [
    'name' => $_POST['name'],
    'email' => $_POST['email'],
    'IP' => getUserIpAddr()
];

$myJSON = json_encode($new_user);
$old_json =  file_get_contents("players.json");
$json_decode = json_decode($old_json);
array_push($json_decode, $new_user);
print_r($json_decode);
$json_file = fopen('players.json', 'w');
fwrite($json_file, json_encode($json_decode));
fclose($json_file);

If I print the $json_decode I get this:

stdClass Object ( 
    [name] => name 
    [email] => [e-mail] 
    [IP] => ::1 
)

with the error message:

array_push() expects parameter 1 to be array, object given in

how do I turn the json content into a array?

Answer 1

don't do json_encode() before array_push()

Use true as second parameter to json_decode()

$new_user = [
    'name' => $_POST['name'],
    'email' => $_POST['email'],
    'IP' => getUserIpAddr()
];

//$myJSON = json_encode($new_user); not needed

$old_json =  file_get_contents("players.json");

$json_decode = json_decode($old_json,true); // true as second parameter

array_push($json_decode, $new_user); // push array not json_encoded value

print_r($json_decode);

$json_file = fopen('players.json', 'w');

fwrite($json_file, json_encode($json_decode));

fclose($json_file);