How to add prefix to ID?

How Do I...
#1

Structure of the pages:

  • Header.php
  • Contents.php
  • AjaxContent.php

There is a select2 in the header.php having ID=W0.

From the contents.php page, I called AjaxContent.php using AJAX, prepared a form element with three more select2 dropdowns, and appended that form to the contents.php page.

Now on the browser document, there are four select2 dropdowns having the ids

  1. ID = W0 - Header.php
  2. ID = W0 - Contents.php
  3. ID = W1 - Contents.php
  4. ID = W2 - Contents.php

So as you can see, a duplicate ID is causing the issue and does not render the select2 properly.

Is there any way to add a prefix to ID so that we can tell select2 to use that to create a unique ID?