下拉菜单中的Bootstrap4向右下拉菜单关闭父菜单

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    下拉菜单
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">选项1</a>
    <a class="dropdown-item" href="#">选项2</a>
    <div class="dropdown-divider"></div>
    <a class="dropdown-item" href="#">选项3</a>
  </div>
</div>

.dropdown-menu-right {
  right: 0;
  left: auto;
}

$('.dropdown-menu a.dropdown-item').on('click', function() {
  $(this).closest('.dropdown').removeClass('show');
});