Online PHP editor | output for Ydthj

<?php class Books{ /* Member variables */ public $price; public $title; /* Member functions */ public function setPrice($par){ $this->price = $par; } public function getPrice(){ echo $this->price.'<br/>'; } public function setTitle($par){ $this->title = $par; } public function getTitle(){ echo $this->title.'<br/>'; } public function __construct($par1 = '',$par2 = ''){ $this->title = $par1; $this->price = $par2; } } class Novel extends Books { public $publisher; public function setPublisher($par){ $this->publisher = $par; } public function getPublisher(){ echo $this->publisher; } } $physics = new Books("Physics for High School" , 2000); $chemistry = new Books("Advanced Chemistry" , 1200); $maths = new Books("Algebra", 3400); $physics->getTitle(); $chemistry->getTitle(); $maths->getTitle(); $physics->getPrice(); $chemistry->getPrice(); $maths->getPrice(); if (class_exists('Novel')) { echo 'yes'; } $pN = new Novel(); $pN->setPublisher("Barnes and Noble"); $pN->getPublisher();