javascript - 如何使用jquery(最好)显示和隐藏无序列表(ul)中的列表项(li)元素？

Question

HTML 文件中的无序列表:

    <ul class="navbar-nav ml-auto" id="authorization">
          <li class="nav-item" class="authorizationLink">
            <a class="nav-link" href="registration.html">Registration</a>
          </li>
          <li class="nav-item" class="authorizationLink">
            <a class="nav-link" href="login.html">Login</a>
          </li>
          <li class="nav-item dropdown" id="usernameDropdown" style="display: none">
              <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
              </a>
              <div class="dropdown-menu" aria-labelledby="navbarDropdown">
                <a class="dropdown-item" href="#">Profile</a>
                <div class="dropdown-divider"></div>
                <a class="dropdown-item" href="#">Logout</a>
              </div>
          </li>
      </ul>
      <button id="someButton">button</button>

我想使用 class="authorizationLink" 隐藏列表项，并在单击按钮时使用 id="navbarDropdown" 显示列表项。到目前为止我已经尝试过:

    $( document ).ready(function() {
        $("#someButton").click(function() {
            $(".authorizationLink").hide();
            $("#usernameDropdown").show();
        })
    }

我尝试了更多的方法，其中一种解决方案有时有效，但大多数时候不起作用。有没有办法使用 jquery 来实现这一点？也许有一些 css 技巧或其他东西？

Answer 1

HTML 元素只能有一个 class 属性。如果有更多类，请将它们合并在同一个字符串中，并用空格分隔。另外，您还需要 jQuery $(document).ready()

的结束括号

    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>
<ul class="navbar-nav ml-auto" id="authorization">
          <li class="nav-item authorizationLink">
            <a class="nav-link" href="registration.html">Registration</a>
          </li>
          <li class="nav-item authorizationLink">
            <a class="nav-link" href="login.html">Login</a>
          </li>
          <li class="nav-item dropdown" id="usernameDropdown" style="display: none">
              <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
              </a>
              <div class="dropdown-menu" aria-labelledby="navbarDropdown">
                <a class="dropdown-item" href="#">Profile</a>
                <div class="dropdown-divider"></div>
                <a class="dropdown-item" href="#">Logout</a>
              </div>
          </li>
      </ul>
      <button id="someButton">button</button>
<script>
    $( document ).ready(function() {
        $("#someButton").click(function() {
            $(".authorizationLink").hide();
            $("#usernameDropdown").show();
        })
    });
</script>