How to get a subset of $_POST array with keys starting with a prefix

Question

Let\'s say my $_POST variable looks like:

 65
    [action] => editpost
    [originalaction] => editpo         


        

Answer 1

function GetPrefixedItemsFromArray($array, $prefix, $remplacePref=FALSE)    {
    $keys = array_keys($array);
    $result = array();

    foreach ($keys as $key) {
        if (strpos($key,$prefix) === 0) {
            if($remplacePref===TRUE){
                $result[str_replace($prefix, "", $key)] = $array[$key];
            }
            elseif($remplacePref!==FALSE && $remplacePref!==""){
                $result[str_replace($prefix, $remplacePref, $key)] = $array[$key];
            }
            else{
                $result[$key] = $array[$key];
            }               
        }
    }
    return $result;
}

Then simply call with $myArray = GetPrefixedItemsFromArray($POST, "empl");.

Answer 2

Starting from PHP 5.6 you can use array_filter along with the option ARRAY_FILTER_USE_KEY.

$employee = array_filter(filter_input_array(INPUT_POST), function($key) {
  return strpos($key, 'empl_') === 0;
}, ARRAY_FILTER_USE_KEY);

For security concerns, you may add FILTER_SANITIZE_* to the filter_input_array function according to your needs, accessing $_POST directly is disadvised and filter_input_array without second parameter falls back to FILTER_UNSAFE_RAW.