默认选择不显示在下拉列表中

This is dynamically loaded dropdown box from a php file. I have put a default option Select Language But this is not displaying once the ajax elements loaded.

How can I make the select language as default even after the ajax items are loaded?

<select id="name">
  <option style="display:none;" selected>Select language</option>
</select>

<?php if (isset($_GET['place']) && $_GET['place'] != '') { ?>

    <script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
    <script>
        $.ajax({
            type: "POST",
            data: {place: '<?= $_GET["place"] ?>'},
            url: 'listplace.php',
            dataType: 'json',
            success: function (json) {
                if (json.option.length) {
                    var $el = $("#name"); 
                    $el.empty(); // remove old options
                    for (var i = 0; i < json.option.length; i++) {
                        $el.append($('<option>',
                            {
                                value: json.option[i],
                                text: json.option[i]
                            }));
                    }
                }else {
                    alert('No data found!');
                }
            }
        });
    </script>

$el.empty() statement removes all the options from the select. You shouldn't remove the first option.

For this, use not method and :first pseudo-class in order to keep the default option.

$el.find('option').not(':first').remove();

Because you need to remove old options, and add new ones without loosing the default "Select language" text, you can do like this:

<select id="name">
  <option style="display:none;" selected>Select language</option>
</select>

<?php if (isset($_GET['place']) && $_GET['place'] != '') { ?>

    <script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
    <script>
        $.ajax({
            type: "POST",
            data: {place: '<?= $_GET["place"] ?>'},
            url: 'listplace.php',
            dataType: 'json',
            success: function (json) {
                if (json.option.length) {
                    var $el = $("#name"); 
                    $el.empty(); // remove old options
                    //adding your default value
                    $el.append('<option selected>Select language value</option>');
                    for (var i = 0; i < json.option.length; i++) {
                        $el.append($('<option>',
                            {
                                value: json.option[i],
                                text: json.option[i]
                            }));
                    }
                }else {
                    alert('No data found!');
                }
            }
        });
    </script>

</div>