Question

My problem is option value which is
<option selected="selected" disabled="disabled">Select a city...</option>
The problem is : despite this option having no value, php code sees its value as * ‘Select a city’*. So, my code if(isset($_POST['city']) returns always true even a city is not choosed. How can I solve this?

Here is html code :

<form id="city_form">

  <select id="city" name="city">
    <option selected="selected" disabled="disabled">Select a city...</option>
    <option value=1 name="city1">City 1</option>
    <option value=2 name="city2">City 2</option>
    <option value=3 name="city3">City 3</option>
    <option value=4 name="city4">City 4</option>
  </select>

  <input type="submit" value="Submit form" id="submit_button" />

</form>
<div id="show_city"></div>

Here is jquery codes :

$('#submit_button').click(function(e) {
  e.preventDefault();
  var data = $('#city_form').serialize();
  $.post(
         "fetch_city.php",
          data,
          function (response) {
             $('#show_city').html(response);
          }
        );
});

Here is fetch_city.php :

if (isset($_POST['city']) && !empty($_POST['city'])) {

  $city_id = $_POST['city']);
  echo $city_id;

} else {
  echo "You did not select a city...!";
}

Answer 1

You can’t. Give it a meaningful sentinel value and ignore the control if that value comes up.

<option selected="selected" disabled="disabled" value="">Select a city...</option>