How to collapse a multidimensional array into a one-dimensional without losing keys?

If correctly understood from the comment, then the task, when accessing the key, is to derive all its possible values ​​from the multidimensional array.

If so, you can stir up this:

  $newArray = []; $commonArray = Array ( [0] => Array ( [0] => Array ( [ID] => 884 [UF_FIRSTNAME] => ТЕСТ [UF_MIDDLENAME] => ТЕСТ [UF_LASTNAME] => ТЕСТ ) [1] => Array ( [ID] => 885 [UF_FIRSTNAME] => ТЕСТ [UF_MIDDLENAME] => ТЕСТ [UF_LASTNAME] => ТЕСТ ) ) ) foreach ($commonArray as $values) { if (!empty($values)) { foreach ($values as $key => $value) { $newArray[$key][] = $value; } } } 

and further we have the following structure

 $newArray = [ 'ID' => [values...], 'UF_FIRSTNAME' => [values...], 'UF_MIDDLENAME' => [values...], 'UF_LASTNAME' => [values...], ] 

and how to deduce this is the next question:

array_unique - if we want to leave only unique values

implode - if we want to output a string with a separator, for example

 echo implode(', ', $newArray['UF_FIRSTNAME']); //все значения из ключей UF_FIRSTNAME 

If you do not use array_unique, then when iterating over the keys, the internal value pointers will correspond as if they were in 1 array. for example

 foreach ($newArray['ID'] as $key => $value) { echo 'ID is ' . $value; echo 'UF_FIRSTNAME for ID ' . $value . ' is ' . $newArray['UF_FIRSTNAME'][$key]; // etc } 

I hope to guess)

Probably you need not what you are asking. If you explain the real problem, they can help you.

In the meantime, I have a fun solution to this problem (just for fun):

 <?php /** * Разворачивает многомерный массив в одномерный, нумеруя ключи */ function aflatten(array $arr, string $keyIdSeparator = ''): array { $result = []; $increments = []; array_walk_recursive($arr, function($item, $key) use($keyIdSeparator, &$result, &$increments) { if ( ! isset($increments[$key])) { $increments[$key] = 0; } $newKey = $key . $keyIdSeparator . $increments[$key]; $result[$newKey] = $item; $increments[$key]++; }); return $result; } $arr = [ [ [ 'ID' => 884, 'UF_FIRSTNAME' => 'ТЕСТ', 'UF_MIDDLENAME' => 'ТЕСТ', 'UF_LASTNAME' => 'ТЕСТ', ], [ 'ID' => 885, 'UF_FIRSTNAME' => 'ТЕСТ', 'UF_MIDDLENAME' => 'ТЕСТ', 'UF_LASTNAME' => 'ТЕСТ', ], ], ]; $keyIdSeparator = '.'; $result = aflatten($arr, $keyIdSeparator); foreach ($result as $key => $value) { $sourceKey = substr($key, 0, strrpos($key, $keyIdSeparator)); echo $sourceKey, ': ', $value, "\n"; } 

All you can do is combine the values ​​of the subarrays under the same keys

 $array = [ [ 'ID' => 884, 'UF_FIRSTNAME' => 'ТЕСТ', 'UF_MIDDLENAME' => 'ТЕСТ', 'UF_LASTNAME' => 'ТЕСТ' ], [ 'ID' => 885, 'UF_FIRSTNAME' => 'ТЕСТ', 'UF_MIDDLENAME' => 'ТЕСТ', 'UF_LASTNAME' => 'ТЕСТ' ] ]; foreach ($array as $key => $value) { foreach ($value as $k => $v) { $new[$k][] = $v; } } print_r($new);