如何将类添加到动态创建的DOM元素或类中

Question

动态创建类category2，category3，category4等。我想添加和删除一些名为active的类，例如class="category2 active"。

这是我尝试将.active类添加到动态创建的类<​​strong> dynamic-class * 中的代码，但是它不起作用：

if (count == 1) {
  $('.dynamic-class' + count).removeClass('active');
  $('.dynamic-class' + 2).addClass('active');
}
if (count == 2) {
  $('.dynamic-class' + count).removeClass('active');
  $('.dynamic-class' + 1).addClass('active');
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="film_listing live_tv">
  <div class="col-sm-2"><img id="11665" class="dynamic-class1" src="images/movies/flowerstv.jpg"></div>
  <div class="col-sm-2"><img id="11666" class="dynamic-class2" src="images/movies/flowerstv.jpg"></div>
</div>

Answer 1

按类名选择时，您缺少.。请尝试以下：

if (count == 1) {
    $('.dynamic-class' + count).removeClass('active');
    count++;
    $('.dynamic-class' + count).addClass('active');
}
if (count == 2) {
    $('.dynamic-class' + count).removeClass('active');
    count--;
    $('.dynamic-class' + count).addClass('active');
}