title: javascript regex - look behind alternative?
body: <p>Here is a regex that works fine in most regex implementations:</p>
  
  <pre><code>(?&lt;!filename)\.js$
  </code></pre>
  
  <p>This matches .js for a string which ends with .js except for filename.js</p>
  
  <p>Javascript doesn't have regex lookbehind. Is anyone able put together an alternative regex which achieve the same result and works in javascript?</p>
  
  <p>Here are some thoughts, but needs helper functions. I was hoping to achieve it just with a regex:
  <a href="http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript" rel="noreferrer">http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript</a></p>