title: How to count Letters inside a string?
body: <p>My Code: </p>
  
  <pre><code>function letterCounter(str) {
      var letters = 0;
      var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
      for (var i=0; i&lt;str.length;i++) {
          if (str[i] === alphabet.split("")) {
              letters = letters + str[i];
          }
      }
      console.log(letterCounter("Hello World!!!1"));
  }
  </code></pre>
  
  <p>I am not sure what mistake I am making and I am getting 0 letters as my answer.
  Thank you.</p>