Online PHP editor | refs for D970D

<?php class Base { protected $quadrat; public function getQuadrat() { echo is_callable($this->quadrat) ? 'Yes' : 'No'; echo "\n"; return $this->quadrat; } } class Test extends Base { public function malzwei($n) { return $n * 2; } public function quadrat($n) { return $n * $n; } } $t = new Test(); $quadrat = $t->getQuadrat(); echo gettype($quadrat); echo call_user_func($quadrat, 3); var_dump(array_map($quadrat, array(1, 2, 3, 4)));