Bootstrap hidden.bs.modal event not firing

Question

I have used the hidden.bs.modal event, but it doesn't work. I tried with the code below. I really don't know what to do.

$('#myModal').on('hidden.bs.modal', function(e) {
  alert('test');
})

// I also tried this:
/*
jQuery(document).ready(function(e) {
  $(document).on('show.bs.modal', '#myModal', function() {
    alert('hi');
  })
});
*/

<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>

<button id="myModal" type="button" class="btn btn-primary" data-toggle="modal" data-target=".bd-example-modal-sm">Small modal</button>

<div id="myModal" class="modal fade bd-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-sm">
    <div class="modal-content">
      ...
    </div>
  </div>
</div>

Answer 1

There's a couple of issues here. Firstly use a single version of jQuery in the page. Using multiple will causes issues such as references to the libraries you include being lost. Secondly, you need to include the Bootstrap stylesheet for the modal to appear correctly in the UI.

Lastly, and most importantly, you're using the #myModal id twice in the DOM on two separate elements. This is invalid. Remove it from the button. It should only be placed on the div which holds the modal content. Try this:

jQuery(function($) {
  $('#myModal').on('hidden.bs.modal', function(e) {
    alert('test');
  });
});

<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

<button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bd-example-modal-sm">Small modal</button>

<div id="myModal" class="modal fade bd-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-sm">
    <div class="modal-content">
      ...
    </div>
  </div>
</div>