小编And*_*ndy的帖子

我的问题适用于我为了更好地理解如何使用OOP而编写的这三个示例类.

class Book {
    //not using getters/setters to save some space
    public $name;
    public $numreads;
}

class BookFactory {
    private $db;
    public function __construct(Database $db) {
        $this->db = $db;
    }
    public function getBook($id) {
        $book = new Book();

        $book->name = $db->query("SELECT name FROM books...");

        $booknumreads = new BookNumRead($this->db, $book);
        $book->numreads = $booknumreads->getFromLocal() + $booknumreads->getFromAnotherSource();

        return $book;
    }
}

class BookNumRead {
    private $db;
    private $book;
    public function __construct(Database $db, Book $book) {
        $this->db = $db;
        $this->book = $book;
    }

    public …