search single dropdown with search textbox code example

Example 1: seach with dropdown list

<!-- Script -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src='select2/dist/js/select2.min.js' type='text/javascript'></script>

<!-- CSS -->
<link href='select2/dist/css/select2.min.css' rel='stylesheet' type='text/css'>

Example 2: search in dropdown

function formatState (state) {
  if (!state.id) {
    return state.text;
  }
  var baseUrl = "/user/pages/images/flags";
  var $state = $(
    '<span><img src="' + baseUrl + '/' + state.element.value.toLowerCase() + '.png" class="img-flag" /> ' + state.text + '</span>'
  );
  return $state;
};

$(".js-example-templating").select2({
  templateResult: formatState
});