Day 13: Abstract Classes
https://www.hackerrank.com/challenges/30-abstract-classes/problem
//Write MyBook class
class MyBook extends Book {
protected $price;
function __construct($t, $a, $p){
parent::__construct($t, $a);
$this->price = $p;
}
public function display(){
print('Title: '.$this->title);
print('Author: '.$this->author);
print('Price: '.$this->price);
}
}