scrap pad

php function of the day

Fairly often in Drupal I get handed arrays that have significant keys, but the values are either a label or false-y. I generally don't care about the items with empty values, or I specifically want to remove them. The solution is to use array_filter($arr) to remove any array items with false-y values. In fact, sometimes I don't even care about the labels at all, in which case I might do array_keys(array_filter($arr)). Examples below.

$arr = array(
  'key1' => 'Label 1',
  'key2' => 'Second Label',
  'key3' => 0,
  'key4' => 'Label No. 4',
  'key5' => 0,
);

$arr_filtered = array_filter($arr);
/*
   $arr_filtered = array(
     'key1' => 'Label 1',
     'key2' => 'Second Label',
     'key4' => 'Label No. 4',
   );
*/

$arr_filtered_keys = array_keys(array_filter($arr));
/*
   $arr_filtered_keys = array(
     'key1',
     'key2',
     'key4',
   );
*/

array_filter() can also take a callback as the second argument, which lets you filter out items on your own terms. See the array_filter() documentation.