recursive search an array on the basis of key in php

Question

I need a php function that will recursively search an array on the basis of key I provided. and want to get an array as return output containing all the values those are mapped with the searched key.

For eg:

[Case] => Array
    (
        [0] => Array
            (
                [CASE_ID] => 2233
                [CHECK_ID] => 57
                [CLIENT_ID] => 78
            )
        [2] => Array
            (
                [CASE_ID] => 9542
                [CHECK_ID] => 45
                [CLIENT_ID] => 18
            )
     )

If I would pass this array and key CHECK_ID , then it should return me an array containing 57,45 . Kindly ask if you need more explanation. Thanks in Advance.

Answer 1

Walking the array and chucking found keys into a new one:

function find_matches($array, $value) {
    $found = array();
    array_walk_recursive($array,
        function ($item, $key) use ($value, &$found) {
            if ($value === $key) {
                $found[] = $item;
            }
        }
    );
    return $found;
}

see http://codepad.viper-7.com/dVmYOT

Have you also considered using find('list') with a fields condition restriction?

Answer 2

Just check each element, filter based on key, convert the outcome to an array:

$filter = function($c, $key) {
    return $key === 'CHECK_ID';
};
$filtered = new CallbackFilterIterator(
    new RecursiveIteratorIterator(
        new RecursiveArrayIterator($array)
    ),
    $filter
);
var_dump(iterator_to_array($filtered, false));

Result:

array(2) {
  [0] =>
  int(57)
  [1] =>
  int(45)
}

Answer 3

function array_rfind($find, $arr) {
  $found = array();
  foreach($arr as $key => $val) {
    if($key == $find)
      $found[] = $val;
    elseif(is_array($val))
      $found = array_merge($found, array_rfind($find, $val));
  }
  return $found;
}