title: RegExp to match lonely or single uppercase letters
body: <p>I am trying to create a pipe in angular, but I cannot seem to wrap my head around regular expressions.</p>
  <p>I am trying to match only lonely or single uppercase letters and split them.
  Let us say for instance I have the following:</p>
  <p><code>thisIsAnApple</code> should return <code>[this, Is, An, Apple]</code></p>
  <p><code>thisIsAString</code> should return <code>[this, Is, AString]</code></p>
  <p><code>BB88GGFR</code> should return <code>[BB88GGFR]</code></p>
  <p>So the plan is to match a capital letter if it is not accompanied by another capital letter.</p>
  <p>This is what I have come up with:</p>
  <pre><code>const regExr = new RegExp(/(?=[A-Z])(?![A-Z]{2,})/g);
  let split = string.split(regExr);
  </code></pre>