show modal in bootstrap 4

1<!-- Button trigger modal -->
2<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">
3  Launch demo modal
4</button>
5
6<!-- Modal -->
7<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
8  <div class="modal-dialog" role="document">
9    <div class="modal-content">
10      <div class="modal-header">
11        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
12        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
13          <span aria-hidden="true">×</span>
14        </button>
15      </div>
16      <div class="modal-body">
17        ...
18      </div>
19      <div class="modal-footer">
20        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
21        <button type="button" class="btn btn-primary">Save changes</button>
22      </div>
23    </div>
24  </div>
25</div>

1<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@mdo">Open modal for @mdo</button>
2<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@fat">Open modal for @fat</button>
3<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@getbootstrap">Open modal for @getbootstrap</button>
4
5<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
6  <div class="modal-dialog" role="document">
7    <div class="modal-content">
8      <div class="modal-header">
9        <h5 class="modal-title" id="exampleModalLabel">New message</h5>
10        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
11          <span aria-hidden="true">×</span>
12        </button>
13      </div>
14      <div class="modal-body">
15        <form>
16          <div class="form-group">
17            <label for="recipient-name" class="col-form-label">Recipient:</label>
18            <input type="text" class="form-control" id="recipient-name">
19          </div>
20          <div class="form-group">
21            <label for="message-text" class="col-form-label">Message:</label>
22            <textarea class="form-control" id="message-text"></textarea>
23          </div>
24        </form>
25      </div>
26      <div class="modal-footer">
27        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
28        <button type="button" class="btn btn-primary">Send message</button>
29      </div>
30    </div>
31  </div>
32</div>