title: How can I edit a specific object in ObservableList?
body: <p>For example, I have an <code>ObservableList</code> which holds two strings:</p>
  
  <pre><code>string1 = "foo"
  string2 = "bar"
  </code></pre>
  
  <p>I want to edit <code>string1</code> so that it becomes "foobaz".</p>
  
  <p>How can I do that?</p>
  
  <p>I've tried using <code>.set(int index, Object element)</code>, but it adds another element, instead of editing the element at that index.</p>