title: DOM onLoad event without jquery
body: <p>HTML code :</p>
  
  <pre><code>&lt;html&gt;
     &lt;head&gt;
     &lt;/head&gt;
     &lt;body&gt;
        &lt;script type="text/javascript" src="/js/colorbook.js"&gt;&lt;/script&gt;
        &lt;script type="text/javascript"&gt;
            book.init();
        &lt;/script&gt;
     &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>JS code :</p>
  
  <pre><code>var book = (function(){
     init = function(){
     console.log ( "initialized")
     }return init();
  }());
  </code></pre>
  
  <p>Question : The above code works. But I am unable to understand how?. Can any of JS guys help me here or guide me how should I start debug this code to understand it.</p>