title: expressJS - path values in App.use to mount a Middleware
body: <p>I'm confused about path in express.use.
  In express document <a href="https://expressjs.com/en/4x/api.html#app.use" rel="nofollow noreferrer">https://expressjs.com/en/4x/api.html#app.use</a></p>
  <p>it said: Path:This will match paths <strong>starting</strong> <strong>with</strong> <strong>/abcd:</strong></p>
  <pre><code>app.use('/abcd', function (req, res, next) {
  next()
  </code></pre>
  <p>})</p>
  <p>Does this mean the '/abcd' in app.use work like regex?, which will match any url starting with /abcd (like <strong>/abcd/efg</strong>)
  Then, it will somehow &quot;remove&quot; the /abcd part in the above url, and pass &quot;/efg&quot; to the middleware function?
  (by middleware, I am referring to the router example here <strong>app.use('/birds', birds)</strong>
  <a href="https://expressjs.com/en/guide/routing.html" rel="nofollow noreferrer">https://expressjs.com/en/guide/routing.html</a>)</p>
  <p>If so, is express.router.use(), router.get(), App.get() works the same way?</p>