title: JavaScript: equivalent regex as PHP
body: <p>I have a regular expression to find the next word of given word 'on' in string for php:</p>
  
  <pre><code>(?&lt;=\bon\s)(\w+)
  </code></pre>
  
  <p>It works perfectly for PHP but for js it gives following error:</p>
  
  <blockquote>
    <p>Uncaught SyntaxError: Invalid regular expression: /(?&lt;=\bon\s)(\w+)/:
    Invalid group</p>
  </blockquote>
  
  <p>What is the equivalent regex for javascript?</p>