如何从数组中删除空字符串。 我不确定天气是来自PHP还是Ajax

I am using Ajax in order to display drop-down list when a product group is selected. My Ajax returns a list from the query page(dropd.php). However the problem is the array consists of some empty space between each element. Hence when I did inspect in chrome below is the output I am getting,

<option value="1">Gear pumps</option>
<option></option>
<option value="2">Piston pumps</option>
<option></option> 

How could I remove "<option></option>" from the drop-down list? If I take option tag out from html what I receive is;

Gear pumps^piston pumps^vane pumps...etc If you can notice the space(^).

Ajax code

<script>
    $(document).ready(function(){
      $('#sel1').on('change', function(){
          $.post("dropd.php",{vals:$("#sel1 option:selected").text()},
          function(data){$.trim($("#sel2").html( data ));});
         });
    });
</script>

dropd.php

<?php 
  require('../config/connection.php'); 
  if($_POST['vals']){   
  $values = mysqli_real_escape_string($dbc,$_POST['vals']);
  $query = "SELECT * FROM prdct_categories WHERE product = '$values'";
  $result = mysqli_query($dbc, $query);
  ?>
    <option value="">Select subgroup</option>
    <?php
    foreach($result as $row)
    { ?>
  <option value="<?php echo $row['id']; ?>"><?php echo $row['subgroup']; ?><option/>        
       <?php
        }
     }
    mysqli_close($dbc);
  ?>

Ajax data goes here

  <div class="form-group">
    <label for="inputsubprdctgrp" class="col-sm-4 control-label" >Product Subgroup</label>
    <div class="col-sm-8">
        <select class="form-control" id="sel2" >

        </select>
    </div>
  </div>

Thanks in advance.

There may be 2 issues:

1. The SQL result gives an empty value which can be fixed by using the array_filter() method:

   $new_result = array_filter($result);

2. You wrote option/ instead of **/option

Hope this helps :)

Just use `

$('#sel2').find('option:empty').remove();`

after you load content from ajax, if you want to do it in javascript, otherwise avoid it in PHP in the first place.

just dont put those values in options if it is blank..

you can use below code.

$result = mysqli_query($dbc, $query);
  ?>
    <option value="">Select subgroup</option>
    <?php
    foreach($result as $row)
    { 
        if(trim($row['subgroup'])!=''){
            ?>
            <option value="<?php echo $row['id']; ?>"><?php echo $row['subgroup']; ?><option/>        
           <?php
        }

     }
    mysqli_close($dbc);
  ?>