Подробности кода Примера Черного списка/Белого списка PHP Массива

$data = [
  {id=>1,name=>a,age=>a},
  {id=>1,name=>b,age=>b},
  {id=>2,name=>c,age=>c},
  {id=>3,name=>f,age=>f},
  {id=>2,name=>d,age=>d},
];

$data = [
  [id=>1,user_info=>[[name=>a,age=>a],[name=>b,age=>b]]],
  [id=>2,user_info=>[[name=>c,age=>c],[name=>d,age=>d]]],
  [id=>3,user_info=>[[name=>f,age=>f]]],
];

/**
 * Array to retrieve data from blacklist
 *@ Param array $arr source array
 *@ Param array $list whitelist
 * @return array
 * @example
 * $arr = ['a'=>1,'b'=>2,'c'=>3,'d'=>4]
 * $list = ['d','c'];
 * $return = ['a'=>1,'b'=>2];
 */
public function array_black_list(Array $arr, Array $list)
{
  return array_diff_key($arr, array_flip($list));
}

/**
 * Array to get data from whitelist
 *@ Param array $arr source array
 *@ Param array $list whitelist
 * @return array
 * @example
 * $arr = ['a'=>1,'b'=>2,'c'=>3,'d'=>4]
 * $list = ['d','c'];
 * $return = ['c'=>3,'d'=>4];
 */
public function array_white_list(Array $arr, Array $list)
{
  return array_intersect_key($arr, array_flip($list));
}

/**
 * repeat data processing (usually leftJoin data structure is perfect)
 * Multiple groups of data queried by leftJoin are modified according to primary_id and saved as fields=>[{},{},{}] similar structures.
 * Effect: $data = [{id => 1, name => a, age => a}, {id = > 1, name = > b, age = > b}, {id = > 2, name = > c, age = > c}, {id = > 3, name = > null, age = > null}], $fieldArr = ['name','age']
 * return [{id=>1,repeat_info=>[{name=>a,age=>a},{name=>b,age=>b}]},{id=>2,repeat_info=>[{name=>c,age=>c}]},{id=>3,repeat_info=>[]}]
 *@ Param $data array original data;
 *@ The fields required by param $field Arr array,
 *@ Param string $primary_key duplicate data credentials; (usually primary key id)
 *@ Param string $repeat_name duplicate data to save the field name of the array
 * @return array
 */
public function dealRepeatData(Array $data, Array $fieldArr, $primary_key = 'id', $repeat_name = 'repeat_info')
{
  $res = [];
  // Unduplicated values are obtained from the blacklist and merged into an array classified by ID.
  foreach ($data as $nre) {
    $res[$nre[$primary_key]] = $res[$nre[$primary_key]] ?? $this->array_black_list($nre, $fieldArr);
  }
  // Get duplicate values from the whitelist and merge them into the $repeat_name field of the blacklist.
  foreach ($data as $re) {
    $res[$re[$primary_key]][$repeat_name][] = $this->array_white_list($re, $fieldArr);
  }
  return array_values($res);
}