title: javascript regex to return letters only
body: <p>My string can be something like A01, B02, C03, possibly AA18 in the future as well.  I thought I could use a regex to get just the letters and work on my regex since I haven't done much with it.  I wrote this function:</p>
  
  <pre><code>function rowOffset(sequence) {
                console.log(sequence);
              var matches = /^[a-zA-Z]+$/.exec(sequence);
              console.log(matches);
              var letter = matches[0].toUpperCase();
              return letter;
  }
  
  var x = "A01";
  console.log(rowOffset(x));
  </code></pre>
  
  <p>My <code>matches</code> continue to be null.  Am I doing this correctly?  Looking at this post, I thought the regex was correct: <a href="https://stackoverflow.com/questions/3532053/regular-expression-for-only-characters-a-z-a-z">Regular expression for only characters a-z, A-Z</a></p>