title: Regular expression to find 3 repeated words
body: <p>I'm trying to create a regular expression which matches the same word 3 times, they are separated by a comma. For example, some inputs would be:</p>
  
  <pre><code>HEY,HEY,HEY - match
  NO,NO,NO - match
  HEY,HI,HEY - no match
  HEY,H,Y - no match
  HEY,NO,HEY - no match
  </code></pre>
  
  <p>How can I go about doing this? I've had a look at some example but they are only good for characters, not words.</p>