3v4l.org

run code in 300+ PHP versions simultaneously
<?php class A { public $state = 1; } class B { public $a; public function __construct() { $this->a = $GLOBALS['a']; } } $GLOBALS['a'] = new A(); $b = new B(); echo $b->a->state . PHP_EOL; $GLOBALS['a']->state++; echo $b->a->state . PHP_EOL; $GLOBALS['a'] = new A(); echo $b->a->state . PHP_EOL; echo $GLOBALS['a']->state . PHP_EOL;
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7
1 2 2 1

preferences:
192.98 ms | 403 KiB | 292 Q