title: Regex test for "number.number.number"
body: <p>I'm trying to test a string to make sure it's a number.number.number.</p>
  
  <p>Example would be <code>10.8.1</code></p>
  
  <p>I found this regex <code>/^\d+$/</code> tests for a number, but how can I add the dots condition?</p>