Online PHP editor | refs for kBkhL

<?php // Everything you enter here will be executed by our servers. Try it! class A { public $b; public function A(B $b = null){ if(is_null($b)) $b = new B(); $this->b = $b; } } class B { public $a; public function B(A $a = null) { if(is_null($a)) $a = new A(); $this->a = $a; } } var_dump(new A(new B(new A())));