- var_dump: documentation ( source)
- array_keys: documentation ( source)
<?php
$foo = new class { private $a = 3; protected $b = 2; public $c = 1; }; $arr = (array)$foo; var_dump($arr); var_dump(array_keys($arr)[0][0]);
$b = array_keys($arr)[2];
var_dump($b);