bootstrap模态框无法调用问题

<button class="btn btn-success " data-toggle="modal" data-target="#myModal">添加</button>

<div id="myModal" class="modal fade" tabindex="-1" role="dialog">
    <div class="modal-dialog" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span
                        aria-hidden="true">×</span></button>
                <h4 class="modal-title">Modal title</h4>
            </div>
            <div class="modal-body">
                <p>One fine body…</p>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
                <button type="button" class="btn btn-primary">Save changes</button>
            </div>
        </div>
        <!-- /.modal-content -->
    </div>
    <!-- /.modal-dialog -->
</div>

 模态框弹不出来，

将调用顺序改成如下，即可正常弹出

<script src="../../jquery-3.3.1.min.js"></script>
<script src="../../bootstrap/js/bootstrap.min.js"></script>