Javascript 引导转盘中的项目数返回0

我正在尝试获取引导转盘中项目的长度（总数）。 但是，我的代码始终返回0:

var totalItems=$（'.carousel item'）.length

数据骑乘在父div中声明：

<div id="carouselExampleIndicators" class="carousel slide carousel-fade my-4 " data-ride="carousel">

我在控制台中遇到一个异常：

$（'.carousel'）.carousel（）不是函数；是未定义的

不确定这两个问题是否相关

旋转木马项目使用旋转木马项目类进行标记：

也许它可以成为图书馆的主题，从官方的引导页面获取图书馆


$（文档）.ready（函数（）{
$（“#旋转木马样本滑动”）。旋转木马({
间隔时间：1000，
骑马：是的
});
控制台.log（$（“.carousel项”）.length）；
});
在您的案例中，旋转木马函数需要通过id调用。旋转木马id是
旋转木马采样指示器
，因此您需要通过id调用它

$('#carouselExampleIndicators').carousel()

这是一个使用模板的示例。
此外，您还放置了
style=“height:400；”
，这不是有效的css规则

style=“height:400px；”“
（注意：400px不会显示标签）

最后，没有标记为活动的第一张幻灯片，因此旋转木马不会启动。使用


在同一张幻灯片上occurs@dancingbush你能发布一个可复制的例子吗？刚刚添加在这里now@dancingbush查看我的更新。此外，fiddle已更新我已将所有库加载到PHP页面的头部，JS是一个外部文件，尝试过的解决方案仍然存在问题
 <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel"  src="images/fullpics/colesbay.jpg" alt="Image 2">
                        <div class="carousel-caption d-none d-md-block text-center">
                            <h5>Second slide label</h5>
                            <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
                          </div>
                    </div>

 <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
   <!--V4 does not support glyphicons so use this CDN and pre-append fa fa to all glphicon glyphicon calls-->
    <link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet">
   <!--Bootstrap JQuery and Popper.js and custom Bootstap JS-->
    <script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>

<!--Main body - Botstrap Carousle-->
        <div class="col-lg-9">
            <div id="carouselExampleIndicators" class="carousel slide carousel-fade my-4 " data-ride="carousel">
                <ol class="carousel-indicators">
                <li data-target="#carouselExampleIndicators" data-slide-to="0"></li>
                <!--
                    <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>-->
                    <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
                <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>

                </ol>
                <!--Set the height of  div class to set height of all images as externa css imageCarsoule to stop jumping-->
                <div  class="carousel-inner" style="height: 400;"  role = "listbox">
                  <!--Remove class="carousel-item-active so we can randomly assign image with carousel.js
                    <div class="carousel-item-active">-->
                    <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel" src="images/fullpics/landscapes/Old Sheds Evandale (Acrylic).tiff" alt="First Mage">

                    </div>
                    <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel"  src="images/fullpics/colesbay.jpg" alt="Image 2">
                        <div class="carousel-caption d-none d-md-block text-center">
                            <h5>Second slide label</h5>
                            <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
                          </div>
                    </div>
                    <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel" src="images/fullpics/landscapes/Sheoaks at Coles Bay (Acrylic & Coloured Pencil).tiff" alt="Image 2">
                        <div class="carousel-caption d-none d-md-block text-center">
                            <h5>third slide label</h5>
                            <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
                          </div>
                    </div>
                    <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel"  src="images/fullpics/landscapes/Winter Drovers (Egg Tempera).jpg" alt="Image 2">
                        <div class="carousel-caption d-none d-md-block text-center">
                            <h5>Fourth slide label</h5>
                            <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
                          </div>
                    </div>
                    <div class="carousel-item">
                        <img class="d-block w-100 img-fluid imageCarousel "src="images/fullpics//landscapes/Early Start (Oil).tiff" alt="Image 2">
                        <div class="carousel-caption d-none d-md-block text-center">
                            <h5>Fifth / Last slide label</h5>
                            <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
                          </div>
                    </div>
                </div>
                <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
                    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
                    <span class="sr-only">Previous</span>
                  </a>
                  <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
                    <span class="carousel-control-next-icon" aria-hidden="true"></span>
                    <span class="sr-only">Next</span>
                  </a>
                </div>

$(document).ready(function() {
    $("#ccarouselExampleIndicators").carousel({
      interval: 1000,
      ride:true
    });
    console.log($(".carousel-item").length);
  });

$('#carouselExampleIndicators').carousel()