title: Regular expression to get class name with specific substring
body: <p>I need a regular expression in javascript that will get a string with a specific substring from a list of space delimited strings.</p>
  
  <p>For example, I have;</p>
  
  <ul>
  <li>widget util cookie i18n-username</li>
  </ul>
  
  <p>I want to be able to return only i18n-username. </p>
  
  <p>How </p>