title: Regex to match 2 or more commas
body: <p>I'm trying to write a regex that will identify whether a string has 2 or more consecutive commas. For example:</p>
  
  <pre class="lang-none prettyprint-override"><code>hello,,457
  ,,,,,
  dog,,,elephant,,,,,
  </code></pre>
  
  <p>Can anyone help on what a valid regex would be?</p>