根据选择值显示或隐藏值

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

<div id="content1" style="display: none;">
  内容1
</div>

<div id="content2" style="display: none;">
  内容2
</div>

function showHideContent() {
  var selectValue = document.getElementById("mySelect").value;

  if (selectValue === "option1") {
    document.getElementById("content1").style.display = "block";
    document.getElementById("content2").style.display = "none";
  } else if (selectValue === "option2") {
    document.getElementById("content1").style.display = "none";
    document.getElementById("content2").style.display = "block";
  } else {
    document.getElementById("content1").style.display = "none";
    document.getElementById("content2").style.display = "none";
  }
}