Javascript accordian -折叠除活动实例之外的所有打开的实例

<div class="accordion">
  <div class="accordion-item">
    <div class="accordion-header">实例1</div>
    <div class="accordion-content">实例1的内容</div>
  </div>
  <div class="accordion-item">
    <div class="accordion-header">实例2</div>
    <div class="accordion-content">实例2的内容</div>
  </div>
  <div class="accordion-item">
    <div class="accordion-header">实例3</div>
    <div class="accordion-content">实例3的内容</div>
  </div>
</div>

.accordion-item {
  border: 1px solid #ccc;
  margin-bottom: 10px;
}

.accordion-header {
  background-color: #f0f0f0;
  padding: 10px;
  cursor: pointer;
}

.accordion-content {
  display: none;
  padding: 10px;
}

var accordionItems = document.getElementsByClassName('accordion-item');

for (var i = 0; i < accordionItems.length; i++) {
  accordionItems[i].addEventListener('click', function() {
    this.classList.toggle('active');
    var content = this.querySelector('.accordion-content');
    if (content.style.display === 'block') {
      content.style.display = 'none';
    } else {
      content.style.display = 'block';
    }
  });
}