How can PHP developers ensure that dropdown options are only displayed when a selection is made?

To ensure that dropdown options are only displayed when a selection is made, PHP developers can use JavaScript to dynamically show or hide the dropdown options based on user interaction. This can be achieved by adding an event listener to the dropdown selection element and toggling the visibility of the dropdown options accordingly.

<select id="dropdown">
  <option value="">Select an option</option>
  <option value="option1">Option 1</option>
  <option value="option2">Option 2</option>
</select>

<script>
document.getElementById('dropdown').addEventListener('change', function() {
  var dropdown = document.getElementById('dropdown');
  var selectedOption = dropdown.options[dropdown.selectedIndex].value;
  
  if(selectedOption !== '') {
    // Show dropdown options
    // Add your code here to display additional dropdown options
  } else {
    // Hide dropdown options
    // Add your code here to hide additional dropdown options
  }
});
</script>