title: Get part of a string using jQuery
body: <p>HTML code:</p>
  
  <pre><code>&lt;div id="block-id-45"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>How can I get number <strong>"45"</strong> of string using <a href="http://en.wikipedia.org/wiki/JQuery" rel="noreferrer">jQuery</a>?</p>