Question

I have this huge array:

array(47) (
    "name" => string(0) ""
    "state" => string(7) "Alabama"
    "city" => string(0) ""
    "country" => string(13) "United States"
    "location" => string(0) ""
    "rooms" => string(0) ""
    "price" => string(0) ""
    "highlights" => array(5) (
        0 => string(0) ""
        1 => string(0) ""
        2 => string(0) ""
        3 => string(0) ""
        4 => string(0) ""
    )
    "specifications_type" => string(0) ""
    "specifications_lotsize" => string(0) ""
    "specifications_apn" => string(0) ""
    "specifications_interest" => string(0) ""
    "specifications_year" => string(0) ""
    "specifications_buildings" => string(0) ""
    "specifications_stories" => string(0) ""
    "specifications_corridors" => string(0) ""
    "financials_room" => string(0) ""
    "financials_other" => string(0) ""
    "financials_total" => string(0) ""
    "financials_multiplier" => string(0) ""
    "financials_caprate" => string(0) ""
    "financials_netincome" => string(0) ""
    "amenities_pool" => string(0) ""
    "amenities_fitness" => string(0) ""
    "amenities_quarters" => string(0) ""
    "amenities_services" => string(0) ""
    "amenities_spa" => string(0) ""
    "amenities_meetspace" => string(0) ""
    "amenities_parkspace" => string(0) ""
    "amenities_others" => string(0) ""
    "facilities_room" => string(0) ""
    "facilities_hvac" => string(0) ""
    "facilities_furnitures" => string(0) ""
    "facilities_tv" => string(0) ""
    "facilities_ref" => string(0) ""
    "facilities_microwave" => string(0) ""
    "consumables_resto" => string(0) ""
    "consumables_restocpct" => string(0) ""
    "consumables_barlounge" => string(0) ""
    "consumables_barloungecpct" => string(0) ""
    "consumables_bevrevenue" => string(0) ""
    "consumables_others" => string(0) ""
    "specifications" => string(100) "{"type":"","lotsize":"","apn":"","interest":"","year":"","buildings":"","stories":"","corridors":""}"
    "consumables" => string(89) "{"resto":"","restocpct":"","barlounge":"","barloungecpct":"","bevrevenue":"","others":""}"
    "amenities" => string(100) "{"type":"","lotsize":"","apn":"","interest":"","year":"","buildings":"","stories":"","corridors":""}"
    "facilities" => string(100) "{"type":"","lotsize":"","apn":"","interest":"","year":"","buildings":"","stories":"","corridors":""}"
    "financials" => string(100) "{"type":"","lotsize":"","apn":"","interest":"","year":"","buildings":"","stories":"","corridors":""}"
)

I want to remove the elements whose keys start with any of the following:
“specifications_”, “amenities_”, “facilities_”, “consumables_”, “financials_”

I have thought of using array_filter with a callback but I have no idea how to do things in the callback. Please help.

Answer 1

You can’t actually use array_filter() for this because it preserves keys but you can’t filter on keys, which is your problem. In that case you may as well just loop.

$prefix = array(
  'specifications_',
  'amenities_',
  'facilities_',
  'consumables_',
  'financials_',
);

$output = array();
foreach ($input as $k => $v) {
  foreach ($prefix as $p) {
    $add = true;
    if (strpos($k, $p) === 0) {
      $add = false;
      break;
    }
  }
  if ($add) {
    $output[$k] = $v;
  }
}

Now this works reasonably well so long as the list of prefixes isn’t that large and the array isn’t that large but there is no need to overcomplicate the solution unless you need it.