JS对象为PHP，然后通过PDO INSERT

I have this JS Object:

var planet = {
owner: 4,
name: "Mars",
loc: [3, 4],
level: 4,
baseIncome: 1000
}

I use ajax to transfer this object to PHP

postPlanets: function(planet){

    planet = JSON.stringify(planet);

    $.ajax({
        type: "POST",
        url: "postGameData.php",
        datatype: "json",
        data: {planet: planet}, 
        error: ajax.error,
        success: ajax.success,
    });

I decode the JSON on php via

if (isset($_POST["planet"]{
    $planet = JSON_decode($_POST["planet"]);
}

I then try to do an INSERT using PDO

public function insertPlanet($planet){

    $stmt = $this->connection->prepare("
        INSERT INTO planets
            (owner, name, x, y, level, baseIncome)
        VALUES
            (:owner, :name, :x, :y, :level, :baseIncome)
    ");

    $stmt->bindParam(":owner", $planet["owner"]);
    $stmt->bindParam(":name", $planet["name"]);
    $stmt->bindParam(":x", $planet["loc"][0]);
    $stmt->bindParam(":y", $planet["loc"][1]);
    $stmt->bindParam(":level", $planet["level"]);
    $stmt->bindParam(":baseIncome", $planet["baseIncome"]);

    $stmt->execute();

    if ($stmt->errorCode() == 0){
        return true;
    }
    else {
        return false;
    }
}

But its not working. I know it breaks once it tries to bind the very first parameter on PDO, but i dont know either way nor how i could possibly debug the prepared statement at all.

What am i doing wrong ?

ERROR RETURN

object(stdClass)#3 (5) {
  ["owner"]=>
  string(3) "sdf"
  ["name"]=>
  string(3) "sdf"
  ["loc"]=>
  array(2) {
    [0]=>
    int(2)
    [1]=>
    int(4)
  }
  ["level"]=>
  string(3) "sdf"
  ["baseIncome"]=>
  string(1) "f"
}
<br />
<b>Fatal error</b>:  Cannot use object of type stdClass as array in <b>D:\SecureWAMP_Portable\htdocs\projectX\DBManager.php</b> on line <b>285</b><br />

285 is the very first BIND attempt.

if it's object I think you can call like $planet->owner not like array $planet['owner'].

You have decoded the data into an stdObject type, have it like the following:

if (isset($_POST["planet"]{
    $planet = JSON_decode($_POST["planet"], true);
}

This way you have the object as an array. stdObject means that you can access your data like: $planet->owner rather than $planet["owner"]. That's what the second true param for json_decode is used for.