title: How to check if character is a letter in Javascript?
body: <p>I am extracting a character in a Javascript string with:</p>
  
  <pre><code>var first = str.charAt(0);
  </code></pre>
  
  <p>and I would like to check whether it is a letter. Strangely, it does not seem like such functionality exists in Javascript. At least I cannot find it.</p>
  
  <p>How can I test this?</p>