3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo implements Iterator { public function current(): Foo { return $this; } public function key(): Foo { return $this; } public function next(): void {} public function rewind(): void {} public function valid(): bool { return true; } } foreach ( new Foo as $key => $value ) { var_dump($key, $value); break; }
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
object(Foo)#1 (0) { } object(Foo)#1 (0) { }

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138.04 ms | 407 KiB | 5 Q