Online PHP editor | refs for Qibd7

<?php class Vehicle { private static $counts = []; public static function getCount() { return self::$counts[static::class]; } public function __construct() { $target =& self::$counts[static::class]; $target++; } } class Bike extends Vehicle {} class Car extends Vehicle {} new Bike; new Bike; new Car; var_dump(Bike::getCount()); var_dump(Car::getCount());