title: Add commas as thousands separator and floating point dot in php
body: <p>I have this</p>
  
  <pre><code>$example = "1234567"
  $subtotal =  number_format($example, 2, '.', '');
  </code></pre>
  
  <p>the return of $subtotal is <code>"1234567.00"</code>
  how to modify the definition of $subtotal, make it like this <code>"1,234,567.00"</code></p>