Answers for "bootstrap 4 modal in w3schools"

css 4 modal

<div class="modal fade" id="exampleModalToggle" aria-hidden="true" aria-labelledby="exampleModalToggleLabel" tabindex="-1">
  <div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalToggleLabel">Modal 1</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        Show a second modal and hide this one with the button below.
      </div>
      <div class="modal-footer">
        <button class="btn btn-primary" data-bs-target="#exampleModalToggle2" data-bs-toggle="modal" data-bs-dismiss="modal">Open second modal</button>
      </div>
    </div>
  </div>
</div>
<div class="modal fade" id="exampleModalToggle2" aria-hidden="true" aria-labelledby="exampleModalToggleLabel2" tabindex="-1">
  <div class="modal-dialog modal-dialog-centered">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalToggleLabel2">Modal 2</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        Hide this modal and show the first with the button below.
      </div>
      <div class="modal-footer">
        <button class="btn btn-primary" data-bs-target="#exampleModalToggle" data-bs-toggle="modal" data-bs-dismiss="modal">Back to first</button>
      </div>
    </div>
  </div>
</div>
<a class="btn btn-primary" data-bs-toggle="modal" href="#exampleModalToggle" role="button">Open first modal</a>

modal html

<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@mdo">Open modal for @mdo</button>
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@fat">Open modal for @fat</button>
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@getbootstrap">Open modal for @getbootstrap</button>

<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">New message</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">×</span>
        </button>
      </div>
      <div class="modal-body">
        <form>
          <div class="form-group">
            <label for="recipient-name" class="col-form-label">Recipient:</label>
            <input type="text" class="form-control" id="recipient-name">
          </div>
          <div class="form-group">
            <label for="message-text" class="col-form-label">Message:</label>
            <textarea class="form-control" id="message-text"></textarea>
          </div>
        </form>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Send message</button>
      </div>
    </div>
  </div>
</div>