Online PHP editor | refs for rquRC

<?php class Car { protected array $tags; public function __get(string $prop): mixed { print("__get($prop) called"); if (property_exists($this, $prop)) { return $this->{$prop}; } } public function __set(string $prop, mixed $val): void { if (property_exists($this, $prop)) { $this->$prop = $val; } } } class CarMapper { public function test(Car $car): void { echo 'そのままだとtrueになる'.PHP_EOL; var_dump(empty($car->tags)); // bool(true) echo '代入するとfalseになる'.PHP_EOL; $tags = $car->tags; var_dump(empty($tags)); // bool(false) } } $car = new Car(); $car->tags = ['tag1']; $carMapper = new CarMapper(); $carMapper->test($car);