JSFiddle - React, Tailwind, and code Playground

HTML

<div class="upload"><br>
  <br>
  <br>
  <input type="hidden" value="" id="SWFUpload_0_3" name="jpg_uploaded_files[]">
  <br>
  <input type="hidden" value="" id="SWFUpload_0_4" name="jpg_uploaded_files[]">
  <br>
  <input type="hidden" value="" id="SWFUpload_0_5" name="jpg_uploaded_files[]">
  <br>
  <input type="hidden" value="" id="SWFUpload_0_6" name="jpg_uploaded_files[]">
  <br>
  <input type="hidden" value="" id="SWFUpload_0_7" name="jpg_uploaded_files[]">
  <br>
  <input type="text" value="" id="SWFUpload_0_8" name="jpg_uploaded_files[]">
  <br>
</div>

JavaScript

alert($('.upload input:hidden').length);