title: How to clear previous text in UITextView before writing text?
body: <p>I want to clear previous text written on UITextView before new text is written on it.
  I did like this.</p>
  
  <pre><code>textView.text = @"";
  textView.text = @"something";
  </code></pre>
  
  <p>But, previous text is not cleared. It overlaps with current text.
  Textview is non-editable.</p>