https://stackoverflow.com/questions/39578074/jquery-wildcards-dont-work-alone-and-with-removeclass

HTML

<div class='delay-1 otherclass'>
delay-1
</div>
<div class='delay-2 otherclass'>
delay-2
</div>
<button type='button'>
click
</button>

CSS

.delay-1 {
  border: 1px solid red;
}
.delay-2 {
  border: 1px solid green;
}

JavaScript

alert($("[class*='delay-']").length)

$("button").click(function() {

    $("[class*='delay-']").each(function() {
      var el = $(this);
      var classList = el.attr('class').split(/\s+/);
      $.each(classList, function(index, item) {
        if (item.startsWith("delay-")) {
          el.removeClass(item);
          var delayTime = parseInt(item.substring(6), 10);
          el.data('data-wow-delay', delayTime + 's');
        }
      });
    });
});