PHP json_encode class private members

The best method to serialize an object with private properties is to implement the \JsonSerializable interface and then implement your own JsonSerialize method to return the data you require to be serialized.

<?php

class Item implements \JsonSerializable
{
    private $var;
    private $var1;
    private $var2;

    public function __construct()
    {
        // ...
    }

    public function jsonSerialize()
    {
        $vars = get_object_vars($this);

        return $vars;
    }
}

json_encode will now serialize your object correctly.