3v4l.org

run code in 300+ PHP versions simultaneously
<?php declare(strict_types=1); class Foo { private array $data = []; public function __set(string $name, $value): void { $this->data[$name] = $value; } public function __isset(string $name): bool { return isset($this->data[$name]); } public function __unset(string $name): void { unset($this->data[$name]); } } $foo = new Foo(); $one = 1; $two = 2; $foo->$one = 'one'; $foo->$two = 'two'; var_dump( isset($foo->$one), // true isset($foo->$two) // true ); unset($foo->$one); var_dump( isset($foo->$one) // false );

preferences:
68.09 ms | 402 KiB | 5 Q