Removing empty items from a single-level array is something trivial in PHP; but it is not so if our array has 2 levels or more. The following function removes empty items from an (multidimensional) array, and returns the resulting array. Please notice that the use of recursion is required because of the array can be of an unknown number of levels, that is, arrays inside the cells of the array, an so on.

This function is useful when by instance, we have a search-form and the user can enter some optional criteria.

  function array_non_empty_items($input) {
    // If it is an element, then just return it
    if (!is_array($input)) {
      return $input;
    }

    $non_empty_items = array();

    foreach ($input as $key => $value) {
      // Ignore empty cells
      if($value) {
        // Use recursion to evaluate cells
        $non_empty_items[$key] = array_non_empty_items($value);
      }
    }

    // Finally return the array without empty items
    return $non_empty_items;
  }

By example, if we pass the following array to the function:

    $anArray = array(
      ‘country’ => ‘CO’,
      ‘region’ => ”,
      ‘city’ => ”,
      ‘features’ => array(
          ‘home’ => array(‘garden’, ‘bedrooms’=>3),
          ‘beach’ => array(‘no_more_than’=>30, ‘yachts_rental’),
          ’supermarkets’ => ”,
          ‘discotheque’ => ”
       )
    );

Then we will obtain an array without empty items, like this:

   $anArray = array(
      ‘country’ => ‘CO’,
      ‘features’ => array(
          ‘home’ => array(‘garden’, ‘bedrooms’=>3),
          ‘beach’ => array(‘no_more_than’=>30, ‘yachts_rental’)
       )
    );