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javascriptjquerybootstrap-5bootstrap-carousel

How to get the index number of active class properly


I am working on this demo. Why am I not able to get the current index number of .carousel-item.active properly?

As you can see when second slide is showing I am still getting the first slide index and so on.

var totalItems = $('.carousel-item').length;
var currentIndex = $('.carousel-item.active').index() + 1;


var myCarousel = document.getElementById('carouselExampleIndicators')
myCarousel.addEventListener('slide.bs.carousel', function() {
  currentIndex = $('.carousel-item.active').index() + 1;
  $('#slide').text('' + currentIndex + ' / ' + totalItems + '');
});
.carousel-item img {
  max-height: 200px !important;
}
.carousel-indicators{

top:16px !important;
  
}
<!doctype html>
<html lang="en">

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <!-- Bootstrap CSS -->
  <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">

  <title>Hello, world!</title>
</head>

<body>
  <div class="container">
    <button type="button" class="btn btn-warning"><span id="slide">1 / 3</span></button>
    <div id="carouselExampleIndicators" class="carousel slide" data-bs-ride="carousel">
      <div class="carousel-indicators">
        <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="0" class="active" aria-current="true" aria-label="Slide 1"></button>
        <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="1" aria-label="Slide 2"></button>
        <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="2" aria-label="Slide 3"></button>
      </div>
      <div class="carousel-inner">
        <div class="carousel-item active">
          <img src="https://placeimg.com/300/280/tech" class="d-block w-100" alt="...">
        </div>
        <div class="carousel-item">
          <img src="https://placeimg.com/300/280/people" class="d-block w-100" alt="...">
        </div>
        <div class="carousel-item">
          <img src="https://placeimg.com/300/280/Place" class="d-block w-100" alt="...">
        </div>
      </div>
      <button class="carousel-control-prev" type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="visually-hidden">Previous</span>
  </button>
      <button class="carousel-control-next" type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="visually-hidden">Next</span>
  </button>
    </div>

    <script src="https://code.jquery.com/jquery-3.1.0.js"></script>


    <script src="https://cdn.jsdelivr.net/npm/@popperjs/[email protected]/dist/umd/popper.min.js" integrity="sha384-7+zCNj/IqJ95wo16oMtfsKbZ9ccEh31eOz1HGyDuCQ6wgnyJNSYdrPa03rtR1zdB" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js" integrity="sha384-QJHtvGhmr9XOIpI6YVutG+2QOK9T+ZnN4kzFN1RtK3zEFEIsxhlmWl5/YESvpZ13" crossorigin="anonymous"></script>

</body>

</html>


Solution

  • For your event, try 'slid.bs.carousel' instead of 'slide.bs.carousel'. slide fires immediately while slid fires after the transition is done

    var totalItems = $('.carousel-item').length;
    var currentIndex = $('.carousel-item.active').index() + 1;
    var myCarousel = document.getElementById('carouselExampleIndicators')
    myCarousel.addEventListener('slid.bs.carousel', function() {
      currentIndex = $('.carousel-item.active').index() + 1;
      $('#slide').text('' + currentIndex + ' / ' + totalItems + '');
    });
    .carousel-item img {
      max-height: 200px !important;
    }
    
    .carousel-indicators {
      top: 16px !important;
    }
    <!-- Bootstrap CSS -->
    <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
    
    
    <div class="container">
      <button type="button" class="btn btn-warning"><span id="slide">1 / 3</span></button>
      <div id="carouselExampleIndicators" class="carousel slide" data-bs-ride="carousel">
        <div class="carousel-indicators">
          <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="0" class="active" aria-current="true" aria-label="Slide 1"></button>
          <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="1" aria-label="Slide 2"></button>
          <button type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide-to="2" aria-label="Slide 3"></button>
        </div>
        <div class="carousel-inner">
          <div class="carousel-item active">
            <img src="https://placeimg.com/300/280/tech" class="d-block w-100" alt="...">
          </div>
          <div class="carousel-item">
            <img src="https://placeimg.com/300/280/people" class="d-block w-100" alt="...">
          </div>
          <div class="carousel-item">
            <img src="https://placeimg.com/300/280/Place" class="d-block w-100" alt="...">
          </div>
        </div>
        <button class="carousel-control-prev" type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide="prev">
        <span class="carousel-control-prev-icon" aria-hidden="true"></span>
        <span class="visually-hidden">Previous</span>
      </button>
        <button class="carousel-control-next" type="button" data-bs-target="#carouselExampleIndicators" data-bs-slide="next">
        <span class="carousel-control-next-icon" aria-hidden="true"></span>
        <span class="visually-hidden">Next</span>
      </button>
      </div>
    
      <script src="https://code.jquery.com/jquery-3.1.0.js"></script>
    
    
      <script src="https://cdn.jsdelivr.net/npm/@popperjs/[email protected]/dist/umd/popper.min.js" integrity="sha384-7+zCNj/IqJ95wo16oMtfsKbZ9ccEh31eOz1HGyDuCQ6wgnyJNSYdrPa03rtR1zdB" crossorigin="anonymous"></script>
      <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js" integrity="sha384-QJHtvGhmr9XOIpI6YVutG+2QOK9T+ZnN4kzFN1RtK3zEFEIsxhlmWl5/YESvpZ13" crossorigin="anonymous"></script>