3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo { public $ref; public function &getRef() { return $this->ref; } public function test() { $this->ref = 123; $local = $this->getRef(); $this->ref = 456; echo $local; } } (new Foo)->test();
Output for 7.0.0 - 7.0.31, 7.1.0 - 7.1.25, 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
123
preferences:
155.93 ms | 404 KiB | 212 Q