title: Creating a new object and keeping it in the array
body: <p>I have a situation when I need to create an object and immediately save it into an array. I have a class <code>Book</code>, and in class <code>Library</code> I have an <code>array BOOKS[]</code></p>
  
  <p>For example, I create  <code>HarryPotter = Book.new("Harry Potter and F_stone", "‎JK Rowling")</code> and then it saves into array <code>BOOKS[]</code> by name of book ("Harry Potter and F_stone").</p>
  
  <p>So, I need a method that can solve this problem.</p>