--TEST-- Lazy objects: property isset initializes object --FILE-- a = $a; $this->b = 2; } } function test(string $name, object $obj) { printf("# %s:\n", $name); var_dump($obj); var_dump(isset($obj->a)); var_dump($obj); } $reflector = new ReflectionClass(C::class); $obj = $reflector->newLazyGhost(function ($obj) { var_dump("initializer"); $obj->__construct(1); }); test('Ghost', $obj); $obj = $reflector->newLazyProxy(function ($obj) { var_dump("initializer"); return new C(1); }); test('Proxy', $obj); --EXPECTF-- # Ghost: lazy ghost object(C)#%d (0) { ["b"]=> uninitialized(int) } string(11) "initializer" string(14) "C::__construct" bool(true) object(C)#%d (2) { ["a"]=> int(1) ["b"]=> int(2) } # Proxy: lazy proxy object(C)#%d (0) { ["b"]=> uninitialized(int) } string(11) "initializer" string(14) "C::__construct" bool(true) lazy proxy object(C)#%d (1) { ["instance"]=> object(C)#%d (2) { ["a"]=> int(1) ["b"]=> int(2) } }