将类从禁用更改为活动

Question

我遇到一些问题，在adventwindow＆lt; = day时将我的课程更改为活动状态，我希望它在true时将类从禁用更改为活动状态。如果有人能提供帮助那就太棒了！

var day = 5;
var adventwindow = 1;

if (adventwindow <= day) {
  document.getElementsByClassName('disable').className = 'active';
}

.door {
  color: #fff;
  font-size: 70px;
  position: absolute;
  top: 0;
  left: 0;
  background-color: #91c1cc;
  box-sizing: border-box;
  border-top: 2px #eee dashed;
  border-right: 2px #eee dashed;
  border-bottom: 2px #eee dashed;
  border-left: 1px #eee solid;
  border-radius: 6px;
  padding: 15px;
  width: 130px;
  height: 130px;
  transform-origin: 0 40%;
  transition: all 0.4s ease-in-out;
  transform-style: preserve-3d;
  text-align: center;
}
a.disable {
  pointer-events: none;
  cursor: default;
}
a.enable {
  pointer-events: auto
}

<a class="disable" href="test">
  <div class="door">1</div>
</a>

Answer 1

getElementsByClassName返回具有给定类名的元素集合。您可以按索引访问元素，从0开始。

document.getElementsByClassName('disable')[0].className = 'active';