title: Kotlin Remove all non alphanumeric characters
body: <p>I am trying to remove all non alphanumeric characters from a string.</p>
  
  <p>I tried using <code>replace()</code> with a regex as followed:</p>
  
  <pre><code>var answer = answerEditText.text.toString()
  Log.d("debug", answer)
  answer = answer.replace("[^A-Za-z0-9 ]", "").toLowerCase()
  Log.d("debug", answer)
  </code></pre>
  
  <blockquote>
    <p>D/debug: Test. ,replace</p>
    
    <p>D/debug: test. ,replace</p>
  </blockquote>
  
  <p>Why are the punctuation characters still present? How to get only the alphanumeric characters?</p>