Online PHP editor | output for U6drD

<?php /* Challenge 2: Implement AnswerInterface and get Question to echo "4". */ class Question { public function __construct(AnswerInterface $answer) { echo "What is 2 + 2?\n"; $answer = $answer->get()->the()->answer(); if ($answer instanceof AnswerInterface) { echo $answer . PHP_EOL; } } } interface AnswerInterface { public function get(); public function the(); public function answer(); } // start editing here class Answer implements AnswerInterface { class get{ class the{ function answer(){ return 4; } } } } // end editing here $answer = new Answer; $question = new Question($answer);