根据在选择选项元素中选择的选项显示隐藏的div元素

<select id="mySelect" onchange="showDiv()">
  <option value="">请选择选项</option>
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<div id="div1" style="display:none;">选项1对应的内容</div>
<div id="div2" style="display:none;">选项2对应的内容</div>
<div id="div3" style="display:none;">选项3对应的内容</div>

function showDiv() {
  var selectElement = document.getElementById("mySelect");
  var selectedValue = selectElement.value;
  
  // 隐藏所有的div元素
  var divElements = document.getElementsByTagName("div");
  for (var i = 0; i < divElements.length; i++) {
    divElements[i].style.display = "none";
  }
  
  // 根据选择的选项值显示对应的div元素
  if (selectedValue === "option1") {
    document.getElementById("div1").style.display = "block";
  } else if (selectedValue === "option2") {
    document.getElementById("div2").style.display = "block";
  } else if (selectedValue === "option3") {
    document.getElementById("div3").style.display = "block";
  }
}

<select id="mySelect" onchange="showDiv()">
  <!-- 选项内容 -->
</select>