Send back to Ajax with OOP - php

Question

New to OOP, figured I'd practice a bit by sending back data from PHP via ajax. What am I doing wrong here? It works if I change the code to procedural. Here's the OOP:
if (isset($_POST['fruity'])) {
$start_fruity = new Fruity_draft();
$start_fruity->send_json();
}
class Fruity_draft {
public $banned = $_POST['banned'];
public $players = $_POST['players'];
public $random_civs = $_POST['random_civs'];
public $array_list = [];
public $send_json['banned'] = $banned;
function __construct($send_json) {
$this->send_json = $send_json;
}
function send_json() {
echo json_encode($this->send_json);
}
}

Answer 1

First of all, you forgot about passing a parameter to the constructor, it expects an array.
function __construct($send_json) {
In your call, you don't send anything
$start_fruity = new Fruity_draft();
This throws a warning, Warning: Missing Argument 1
and a notice, Notice: Undefined variable: send_json
Second, you should move the initialization of the class variables in the constructor.
class Fruity_draft {
public $banned;
public $players;
public $random_civs;
public $array_list;
public $send_json;
function __construct($send_json) {
$this->banned = 'banned';
$this->players = 'players';
$this->random_civs = 'random_civs';
$this->send_json = $send_json;
$this->send_json['banned'] = $this->banned;
}
...
}

Answer 2

That's not really OOP :). You should return something from the class, not echo.
Also, you should send data from other function to the class.. in the constructor or with a method set_post_data() or something...
Simple:
if (isset($_POST['fruity'])) {
$start_fruity = new Fruity_draft($_POST);
echo $start_fruity->get_json_response();
}
class Fruity_draft {
private $postData;
function __construct($postData) {
$this->postData = $postData;
}
function get_json_response() {
return json_encode($this->postData['banned']);
}
}