js为select

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

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

const selectElement = document.getElementById('mySelect');
const selectedValue = selectElement.value;
console.log(selectedValue);

const selectElement = document.getElementById('mySelect');
selectElement.value = 'option2'; // 设置选中Option 2

const selectElement = document.getElementById('mySelect');
const newOption = document.createElement('option');
newOption.value = 'option4';
newOption.text = 'Option 4';
selectElement.add(newOption);

const selectElement = document.getElementById('mySelect');
selectElement.remove(0); // 删除第一个选项

const selectElement = document.getElementById('mySelect');
selectElement.addEventListener('change', function() {
  console.log('Selected value:', this.value);
});

<select id="mySelect" multiple>
  <!-- options -->
</select>