Behavioral\Iterator restructured

Behavioral/Iterator/BookList.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace DesignPatterns\Behavioral\Iterator;
+
+class BookList implements \Countable
+{
+
+    private $books;
+
+    public function getBook($bookNumberToGet)
+    {
+        if ((int)$bookNumberToGet <= $this->count()) {
+            return $this->books[$bookNumberToGet];
+        }
+
+        return NULL;
+    }
+
+    public function addBook(Book $book)
+    {
+        $this->books[] = $book;
+
+        return $this->count();
+    }
+
+    public function removeBook(Book $bookToRemove)
+    {
+        foreach ($this as $key => $book) {
+            /** @var Book $book */
+            if ($book->getAuthorAndTitle() === $bookToRemove->getAuthorAndTitle()) {
+                unset($this->books[$key]);
+            }
+        }
+
+        return $this->count();
+    }
+
+    public function count()
+    {
+        return count($this->books);
+    }
+}