如何在semantic-ui中创建占位符？

I am using https://semantic-ui.com/modules/dropdown.html plugin and I have to display the placeholder. I am retrieving data from the database which is working but the placeholder is not displaying.

Note:- If I remove PHP code than it is displaying placeholder.

I tried

$('select.dropdown').dropdown({placeholder:'select option'});

and also tried

<option value="" selected="selected" disabled >Select option</option>

but not working. Please check my code and assist me.

    <select  class="ui fluid search dropdown" id='select-super'>
   <option value="">Select Option</option>

      <?php while($row = mysqli_fetch_array($learn_teach_result)):;?>
                    <option value="<?php echo $row['email'];?>"><?php echo $row['email'];?></option>
                <?php endwhile;?> 
    </select>

What I did. I add placeholder inside While. I don't know it is right or wrong but working for me.

Thanks, MR.Gibbok, With the help of your comment I got my solution

<select  class="ui fluid search dropdown" id='select-super'>
  <?php while($row = mysqli_fetch_array($learn_teach_result)):;?>
   <option value="">Select Option</option>
   <option value="<?php echo $row['email'];?>"><?php echo $row['email'];?></option>
    <?php endwhile;?> 
</select>

Try to use an option with no value, this data should be present in your array in the PHP.

Example:

<div class="another dropdown example">
  <select class="ui dropdown">
    <option value="">Gender</option> <!-- your placeholder -->
    <option value="1">Male</option>
    <option value="0">Female</option>
  </select>
</div>

Try below code.

<select  class="ui fluid search dropdown" id='select-super'>
   <option value="">Select Option</option>
  <?php while($row = mysqli_fetch_array($learn_teach_result)):;?>
            <option value="<?php echo $row['email'];?>"><?php echo $row['email'];?></option>
        <?php endwhile;?> 
</select>