title: Subscribe to array changes
body: <p>I'm trying to use RxJS in an existing project that uses jQuery. Every time the button is clicked a new value is pushed to <code>users</code>. How do I see changes to <code>users</code> in <code>of(users).subscribe(...)</code>?</p>
  
  <pre><code>&lt;button class="hello"&gt;Hello&lt;/button&gt;
  
  &lt;script src="https://unpkg.com/rxjs/bundles/rxjs.umd.min.js"&gt;&lt;/script&gt;
  
  const { of } = rxjs
  
  let users = [
    { a: "b" }
  ]
  
  of(users).subscribe(data =&gt; {
    console.log(data)
  })
  
  jQuery(document).on('click', '.hello', function () {
    users.push({ c: 'd' })
  })
  </code></pre>