Laravel使用ajax选择下拉列表

<select id="myDropdown">
  <option value="1">Option 1</option>
  <option value="2">Option 2</option>
  <option value="3">Option 3</option>
</select>

<script>
  document.getElementById('myDropdown').addEventListener('change', function() {
    var selectedValue = this.value;
    var xhr = new XMLHttpRequest();
    xhr.open('GET', '/ajax/select-dropdown/' + selectedValue);
    xhr.onreadystatechange = function() {
      if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
        var response = JSON.parse(xhr.responseText);
        // 更新下拉列表的选项
        // ...
      }
    };
    xhr.send();
  });
</script>

Route::get('/ajax/select-dropdown/{selectedValue}', 'DropdownController@getOptions');

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class DropdownController extends Controller
{
    public function getOptions($selectedValue)
    {
        // 根据选择的值查询数据库或执行其他逻辑操作
        // ...

        // 构建响应数据
        $options = [
            ['value' => '4', 'text' => 'Option 4'],
            ['value' => '5', 'text' => 'Option 5'],
            ['value' => '6', 'text' => 'Option 6'],
        ];

        return response()->json($options);
    }
}