js选项框

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

<script>
  document.getElementById('singleSelect').addEventListener('change', function() {
    console.log('Selected:', this.value);
  });
</script>

<select id="multiSelect" multiple>
  <option value="option1">Option 1</option>
  <option value="option2">Option 2</option>
  <option value="option3">Option 3</option>
</select>

<script>
  document.getElementById('multiSelect').addEventListener('change', function() {
    console.log('Selected:', Array.from(this.selectedOptions).map(option => option.value));
  });
</script>