$my_array = ['foo' => 1, 'hello' => 'world']; $allowed = ['foo', 'bar']; $filtered = array_filter( $my_array, function ($key) use ($allowed) { return in_array($key, $allowed); }, ARRAY_FILTER_USE_KEY );
?php $data= [ 0 => [1, 'test1'], 1 => [2, 'test2'], 2 => [3, 'test3'], ]; $ids = array_map(function($item) { return $item[0]; }, $data); var_dump($ids);