js下拉列表框事件

<select id="mySelect">
  <option value="option1">Option 1</option>
  <option value="option2">Option 2</option>
  <option value="option3">Option 3</option>
</select>
<div id="result"></div>

document.getElementById('mySelect').addEventListener('change', function() {
  var selectedValue = this.value;
  var resultDiv = document.getElementById('result');
  
  // 根据选择的值执行不同的操作
  switch (selectedValue) {
    case 'option1':
      resultDiv.textContent = 'You selected Option 1';
      break;
    case 'option2':
      resultDiv.textContent = 'You selected Option 2';
      break;
    case 'option3':
      resultDiv.textContent = 'You selected Option 3';
      break;
    default:
      resultDiv.textContent = '';
  }
});