HTML中Wow.js无法运行：是初始化错误还是脚本引用错误？

问题排查与修复 #

存在的问题 #

• 资源引用错误：把animate.css样式文件当成脚本放在<script>标签中加载，同时重复加载了3.3.0和4.1.1两个版本的animate.css，出现版本冲突
• 初始化时机错误：wow的初始化代码写在<head>标签内，执行时页面DOM还未完全渲染，wow无法识别到需要绑定动画的元素
• 类名规则不匹配：你引用的animate.css 4.x版本修改了默认类名规则，所有动画类需要加animate__前缀，旧版的animated、zoomIn类名无法触发动画
• 元素无可见性：第一个绑定动画的div没有内容也没有设置高度，就算动画正常运行也看不到效果

修复方法 #

1. 删掉<head>里错误引入的<script src="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.3.0/animate.css"></script>，只保留4.1.1版本的animate.css样式引用
2. 把wow.js的引入和初始化代码移动到</body>标签之前，保证DOM加载完成后再执行初始化
3. 调整动画元素类名，或者初始化wow时添加适配旧类名的配置，两种方案二选一：
   • 方案1：修改元素类名，把animated wow zoomIn改成wow animate__animated animate__zoomIn
   • 方案2：初始化时传入配置，不用修改现有类名：

   new WOW({
     animateClass: 'animated',
     offset: 100
   }).init();
   

4. 给绑定动画的元素添加内容或者设置最小高度，比如给.bg类加min-height: 300px的样式

修复后核心代码示例 #

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Okan Sen</title>
  <link rel="shortcut icon" type="image/jpg" href="OKANSENLogoWineRed.jpg">
  <!-- 只保留正确的animate.css样式引用 -->
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/4.1.1/animate.min.css">
  <link rel="stylesheet" href="css/bootstrap.min.css">
  <link rel="stylesheet" type="text/css" href="global.css">
  <style>
    /* 给动画元素加最小高度方便观测效果 */
    .bg {
      min-height: 300px;
      background: #f5f5f5;
    }
    .sec1 {
      min-height: 500px;
    }
  </style>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
  <script src="https://unpkg.com/@popperjs/core@2.4.0/dist/umd/popper.min.js"></script>
  <script src="js/bootstrap.min.js"></script>
</head>
<body>
  <!-- 原有导航栏代码不变 -->
  <nav class="navbar navbar-expand-lg navbar-light bg-transparent">
    <div class="container-fluid">
      <a class="navbar-brand" href="#">OKAN</a>
      <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <ul class="navbar-nav me-auto mb-2 mb-lg-0">
          <li class="nav-item">
            <a class="nav-link active" aria-current="page" href="#">Home</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Link</a>
          </li>
          <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
              Dropdown
            </a>
            <ul class="dropdown-menu" aria-labelledby="navbarDropdown">
              <li><a class="dropdown-item" href="#">Action</a></li>
              <li><a class="dropdown-item" href="#">Another action</a></li>
              <li><hr class="dropdown-divider"></li>
              <li><a class="dropdown-item" href="#">Something else here</a></li>
            </ul>
          </li>
          <li class="nav-item">
            <a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
          </li>
        </ul>
        <form class="d-flex">
          <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
          <button class="btn btn-outline-success" type="submit">Search</button>
        </form>
      </div>
    </div>
  </nav>
  <div class="container-fluid bg wow animate__animated animate__zoomIn"></div>
  <section class="sec1 wow animate__animated animate__zoomIn">
    <h1>LELELELELEL</h1>
  </section>
  <!-- wow相关代码移到body末尾 -->
  <script src="https://cdnjs.cloudflare.com/ajax/libs/wow/1.1.2/wow.min.js"></script>
  <script>
    new WOW().init();
  </script>
</body>
</html>

内容的提问来源于stack exchange，提问作者sad_pug